Engineering the coupling between host-lattice phonons and doped Cr3+ ions is pivotal for regulating optical properties of broadband near-infrared (NIR) phosphorsand prompting their applications. Here, we investigate Ca2Ga0.99-xInxNbO6:0.01Cr3+ (x = 0-0.99) phosphors to elucidate how Ga/In substitution-induced B-site disorder tunes the crystal structure, vibrational modes, Cr3+ excited bands, and excitation-relaxation dynamics. A gradual evolution from an ordered framework to a disordered one is revealed through XRD, Raman, and 71Ga ssNMR measurements, resulting in symmetry breaking and activation of low-frequency phonons. The PLE spectra demonstrate composition-driven tuning of the host-Cr3+ hybridized excited bands, yielding two dominant peaks at ∼385 and 460 nm for x = 0.495, which match well with commercial UV and blue LEDs emissions, enabling dual-mode excitation. Huang-Rhys factor S  ≈ 3.8 for ion-lattice coupling and Dq/B ≈ 2.05 for crystal field effect are determined by fitting the phonon sidebands using the multimode Brownian oscillator model and Tanabe-Sugano model analysis. It is further shown that increasing In3+ content strengthens phonon-assisted nonradiative relaxation within the split 4T2 (4F) manifold, thereby resulting in thermal redistribution of luminescence intensity and shortened lifetimes. Overall, adjusting B-site disorder provides an effective handle to engineer impurity-host interactions and tailor the performance of Cr3+-activated NIR phosphors.

DOI:10.1016/j.optlastec.2024.112121, Abstrct: The conventional tilted-wave light source (TWL) features high intensity and thick passive waveguide with thickness of hundreds of micrometers or more. However, this large thickness of waveguide prevents its application in the current Si photonic integrated circuits or chips (PICs) due to the requirement of planar technique. Hence, TWL with thin passive waveguide is demanded for Si PICs. In this work, firstly, Si nanocrystal-based TW light emission in thin passive waveguide is simulated in search of allowed TW optical modes. Then, a TWL device identical to the simulated one is fabricated and its photoluminescence (PL) emission is measured. The emitting light covers the range from 650 to 850 nm in wavelength. PL peaks with narrow line widths are observed and are consistent with the simulated TW modes in peak position, mode spacing and emission angle dependence of the allowed modes. Meanwhile, light amplification of the TW modes is observed. Since Si nanocrystals are a lasing material with a wide gain spectrum covering the whole PL range, typical criteria of lasing of the TWL are tested. The results suggest that Si nanocrystal-based TW lasing in thin passive waveguide can be available.

DOI:10.1016/j.cjph.2025.06.030, Abstract: A novel erbium (Er3+)-doped Si rich oxide (EDSRO) thin film embedded with Si nanocrystals (SiNCs) is developed, which shows near-infrared luminescence at lambda = 1540 nm. The EDSRO here makes use of high solubility of Er3+ in SiO2, with SiNCs acting as sensitizers to excite Er3+ions. High photoluminescence quantum yield (PLQY) of the pristine EDSRO is obtained to be 3.3 After treatments of the EDSRO by hydrogen passivation, ytterbium-ions doping, and the introduction of extra SiNCs in sequence, further higher PLQY is achieved to be 20.6 %. Meanwhile, the net optical gain finally attained is 272 cm-1 or 24.3 dB/cm. Both of the PLQY and optical gain are one or two orders of magnitude larger than those of typical erbium-doped Si rich oxides previously reported. The energy transfer efficiency from SiNCs to Er3+ is 11.48 %. The results reported here may find applications in developing highly efficient erbium-doped light sources for optical communication.

DOI:10.1002/lpor.202402164, Abstrct: Silicon (Si) light source has profound significance in monolithic integrated Si photonics. However, its luminance remains too low to meet practical use that usually requires > 10000 cd m(-)(2). Here, an all-inorganic Si nanocrystal (SiNC) white light-emitting diode (WLED) with a continuous emission spectrum spanning approximate to 400-900 nm in wavelength, is reported. The architecture of the WLED comprises front electrode of Ag grids and transparent-conducting-oxide/electron transport layer (ETL) of ZnO/front charge confinement layer (CCL) of SiO2/active layer of low-resistivity SiNC composite thin film/rear CCL of SiO2/hole transport layer (HTL) of MoO3/textured p-Si substrate/rear electrode of aluminum/heat radiator. The main procedures for achieving high luminance here include combined applications of high-pressure ammonia passivation of the active layer, which enhances its photoluminescence quantum yield significantly, and texturing of p-Si substrate, which boosts the light extraction and charge injection effectively. With an optimized combination of passivation and texturing, luminance of 10751 cd m(-)(2) is achieved with external quantum efficiency (EQE) of 0.26%. After a Peltier cooler is further applied, luminance of 12363 cd m(-)(2) is attained with EQE of 0.30%. Following further technical iterations, this highly bright SiNC WLED shall find applications in monolithic integrated Si photonics and even Si general lighting.

Recent rigorous demonstration of self-absorption (SA) effects of internal luminescence in solids [H. G. Ye et al. Sci. Bull. 62, 1525 (2017)] has opened a breach in the solid wall behind which the SA processes and effects occur but cannot be directly probed inside the solid. Herein, we attempt to present a further theoretical consideration of the SA effects of internal luminescence occurring inside a nanowire with Urbach band-tail states. The consideration begins with an ideal luminescence spectrum with delta-line shape and then goes to the cases of luminescence spectra with Lorentzian, Gaussian, and localized-state ensemble (LSE) line shapes, respectively. A quantitative consideration of the SA effects in the spectral features of external luminescence spectra along with the nanowire axis is established for the variables of temperature, transmission distance, and photon energy. Generally, it is found that the self-absorption of internal luminescence can have a significant impact on the spectral features of external luminescence, depending on the three above-mentioned variables. In particular, the influence of SA on the three key spectral parameters, including intensity, peak position, and full width at half maximum (FWHM) of external LSE luminescence, is unveiled, providing a quantitative explanation for a few experimental phenomena reported in the literature. In addition, some interesting phenomena, i.e., nearly no peak shift with increasing the transmission distance, etc., have been predicted. These results more deeply establish the theoretical foundation of self-absorption, which is of positive significance for the regulation and enhancement of optoelectronic devices.

Monolayer tungsten disulfide (1L-WS2) is an atomically layered semiconductor with direct bandgap and novel physical and optical properties being extensively investigated by researchers worldwide. Here we present an in-depth investigation on tunability of valley-electronic and optical properties of 1L-WS2 under large biaxial tensile strain with in situ microreflectance and photoluminescence spectroscopic techniques. At room temperature, a red shift as large as 220.0 meV in the A-exciton luminescence energy and direct-to-indirect bandgap transition was observed in the 1L-WS2 sample under biaxial strain. Notably, the excitonic line width exhibits a strain-dependent dichotomic behaviors: below 2.5% strain, the line width narrows by 11.0 meV due to the enhanced KK-KQ valley separation, while above 2.5%, it broadens by 8.0 meV due to the activation of K Gamma-mediated intervalley scattering. Reflectance spectroscopic measurements reveal that strain-driven renormalization of spin-orbit coupling splitting can be as large as 47.0 meV. Furthermore, the Stokes shift between the absorption and luminescence peaks can be effectively tuned by biaxial strain due to the regulation of exciton-phonon coupling and the bandgap transition from a direct gap to an indirect gap by the biaxial strain. This work establishes a framework for mechanically tailoring excitonic optical properties, spin-valley interactions, and band structures in 2D quantum materials, with implications for strain-tunable optoelectronic and valleytronic devices.

Efficient anti-Stokes vibronic luminescence (ASVL) in solids is of both scientific and technological interest. However, it is challenging to achieve an efficient ASVL in solids under the excitation of incoherent, weak light. In this article, we present an experimental demonstration of a pronounced ASVL in Mn4+-activated K2SiF6 microcrystal phosphor under the excitation of microwatt continuous-wave incoherent light at room temperature. Meanwhile, a clear phonon resonance enhancement effect is demonstrated in the ASVL luminescence. These findings demonstrate the advantages of the efficient ASVL in solids compared with the conventional two-photon upconversion luminescence.

This study investigates the variable-temperature R-lines luminescence spectra of Cr3+ ions in a composite solid comprising alpha-Al2O3 and borate fluorescent glass. A divergence in the thermal broadening (Delta Gamma) of the R1 and R2 lines is observed at temperatures above 140 K. The experimental data were analyzed using McCumber-Sturge theory, incorporating the significant effects of acoustic phonon scattering on the effective Debye temperatures. The thermal broadening of both R-lines was found to strongly depend on excitation energy over a broad range. Furthermore, the excitations at the low-energy side of 4A2 -> 4T2 band exhibited pronounced negative thermal quenching behaviors in both R-lines. These findings provide new insights into the complex many-body interactions underlying the luminescence of functional ions in solids and offer promising opportunities for regulating the thermal behavior of Cr3+ ions' R-lines.

Distinctive valley structures of the energy band in two-dimensional (2D) transition metal dichalcogenides (TMDs) offer various potential momentum-forbidden dark excitons, which significantly alter the decoherence of bright direct KK excitons, mainly via phonon-assisted intervalley scatterings. Nevertheless, the energy position influence of the intervalley dark excitons on the bright exciton decoherence has been rarely investigated. Herein, we report on a systematic combined study of optical spectroscopic experiments and quantum theory calculations for demonstrating the subject. At room temperature, external biaxial strain was applied to mono-, bi-, and trilayer WS2 flakes; meanwhile, reflectance spectra were measured, followed by a quantum Rabi theory calculation to determine the homogeneous line widths of the bright KK excitons. It is unraveled that the homogeneous broadenings of all three flakes show non-monotonic dependence on strain: Decrease first and then turn to increase. Furthermore, the turning strain becomes larger for the thicker flakes. In order to quantitatively interpret the phenomenon, various individual contributions to the homogeneous broadening were calculated with the variational Ansatz, exhibiting an almost linear relationship with external strain. In particular, the energy positions of the intervalley dark excitons were revealed as an important factor tuning the bright excitonic decoherence. Enhancement coefficients of the Gamma K, K Lambda, and K Lambda' intervalley scatterings, namely, xi Gamma K , xi K Lambda, and xi K Lambda' , were thus defined and inferred to be approximately -0.1, -0.34, and -0.4, respectively. These findings demonstrate the important roles of the intervalley dark exciton energy positions in bright exciton decoherence, offering insights into the many-body physics in 2D semiconductor systems.

Excitons and phonons are the two fundamental types of quasiparticles in solids including atomically layered two-dimensional (2D) transition metal dichalcogenides (TMDs). They themselves and their interactions play a central role in determining the optical properties of 2D-TMDs. Herein, we present a combined study on effects of environmental dielectric screening on the optical properties of excitons and the exciton-phonon scattering in a series of WS2 monolayers with different environmental dielectric screenings via reflectance spectroscopic measurements and microscopic calculations. As the dielectric screening increases, the linewidth of the A-exciton resonance structure exhibits a significant narrowing and less dependence on temperature. Microscopic theoretical analysis based on the variational Ansatz shows that the noticeable reduction in both radiative recombination rate and phonon-assisted intervalley scattering of excitons result in the observed phenomenon due to the reduction of exciton Bohr radius caused by the increase of the dielectric screening. In this study, we demonstrate that dielectric engineering can offer an effective approach for regulating the excitonic effects and investigating the complicated exciton-phonon interactions in ultimate 2D monolayer systems.

Luminescence from high-lying excited states, such as the 2G9/2 level of Er3+, has been rarely explored due to its low population and complex excitation mechanisms. However, such luminescence carries important information of high-lying excited states, and hence offers a unique probe for understanding temperature-driven dynamics and phonon-mediated processes in luminescence upconversion systems. Herein, we report temperature-dependent upconversion photoluminescence measurements of Er3+ in Er3+-Yb3+ co-doped transparent ceramics, with a particular focus on transitions involving closely spaced Stark-split sub-levels in the violet emission band. Two excitation pathways are employed to investigate the thermal behavior mediated by phonons. The observed negative thermal quenching phenomenon under 980 nm excitation is well described through a rate-equation-based model that includes thermally coupled Stark sub-levels, phonon-assisted optical excitations and multi-phonon nonradiative relaxation. These insights into the phonon-assisted population dynamics provide a physical basis for the future development of optical thermometric applications.

DOI:10.1002/pssa.202400563, Abstrct: A combined approach of band bending is employed to enhance the near-infrared (NIR) photovoltaic (PV) response of a Si/Au Schottky junction (SHJ) device. As a reference, the basic architecture of the SHJ device consists of textured n-Si and gold nanoparticles (Au NPs). Its photoelectric conversion efficiency at 1319 nm wavelength is 0.0302%. A series of band-bending approaches are then applied to the reference device in sequence, aiming to minimize the electric loss of the structure by strengthening built-in electric field. These approaches include introductions of an Al2O3 layer for front field passivation, a p+-Si layer to form a p+n-like junction at the front of the device and a SiO2 layer for rear field passivation. With these modifications, under 1319 nm illumination, the open-circuit voltage eventually increases by 14%, the short-circuit current increases by 18% and the photoelectric conversion efficiency of the device increases by 66% to reach 0.0501%. The results of this work propose a strategy to minimize the electric loss in an NIR PV device. A near-infrared silicon photovoltaic device based on Schottky junction is realized in this work. Aiming at minimizing the electric loss in the device, a series of band-bending approaches are sequentially applied to enhance the total built-in electric field. As a result, the photoelectric conversion efficiency of the structure increases by 66%.image (c) 2024 WILEY-VCH GmbH

DOI:10.1063/5.0191000, Abstrct: A silicon nanocrystal (Si NC) white light-emitting (λ = ∼400–900 nm) thin film with a relatively low resistivity of 1.6 × 104 Ω m has been prepared as an active medium for electrically driven Si light sources. The average size of Si NC is 2.4 ± 0.4 nm. To enhance the light emission efficiency of this low-resistivity Si NC thin film, approach of hydrogen passivation suitable for the traditional high-resistivity (1.2 × 107 Ω m in this work for example) red light-emitting Si NC thin film has been tried and found unavailable unfortunately. Our first principles simulation shows that Si NCs bonded to −O, −NH2, −OH, and −H ligands are responsible for red, green, and blue (RGB) primary color emissions in this white light-emitting sample, respectively. Passivation of the sample in NH3 and H2O atmosphere is then conducted, aiming to increase the number of the RGB light emitters. The light emission is significantly enhanced, with photoluminescence intensity, photoluminescence quantum yield, electroluminescence intensity, and net optical gains increased by factors of 4.6, 4.2, 4.0, and ∼3.0, respectively, after 10-day passivation. Further enhancements are expected for longer passivation.

DOI:10.1063/5.0226677, Abstrct: Effective suppression of dark current is essential for improving the performance of bulk defect-mediated absorption (BDA) photodetectors. Blocked impurity band (BIB) infrared detectors have been developed and utilized from mid-infrared to far-infrared wavelength regions for low noise. In this work, a blocking layer of dark current was applied to a BDA short-wave infrared (SWIR) photodetector, emulating the concept of BIB detectors. ZnO was chosen as the blocking layer to impede the transport of electrons from the bulk defect levels due to its wide bandgap and to allow the photocurrent to remain nearly unaffected by proper positioning of the conduction band minimum. After introducing the ZnO blocking layer, the dark current density of the photodetector was reduced by two orders of magnitude, and the specific detectivity was enhanced by one order of magnitude. The effects of TiO2 and WO3 as blocking layers were also investigated and compared with ZnO. This work offers an effective method for enhancing detectivity in SWIR BDA photodetection by suppressing the dark current efficiently.

Anomalous thermal behaviors of excitonic luminescence in CsPbBr3 perovskite quantum dots (PQDs) were observed. It is found that the main luminescence peak originated from the excitonic radiative recombination assisted by the longitudinal-optical (LO) phonon, and its integrated intensity first declines as the temperature varies from 10 to 150 K and then turns to increase at ∼160 K, reaching a maximum value at 300 K. A model considering the thermal detrapping and transfer of electrons from a trap level is developed to interpret these abnormal thermal behaviors of the luminescence from the PQDs. On the other hand, the quantum-mechanical multimode Brownian oscillator model was employed to unravel that the Huang–Rhys factor exclusively characterizing the exciton–phonon coupling in the studied CsPbBr3 PQDs decreases from 1.65 at 10 K to 1.31 at 200 K.

In this study, the optical properties of Sr2LuNbO6:Mn4+ deep-red phosphor synthesized with a molten salt solid-phase method were investigated in detail by using photoluminescence (PL), PL excitation (PLE), time-resolved PL, and Raman spectroscopic techniques. At room temperature, the PL spectra of the phosphor sample show a stepped shape. At cryogenic temperatures, however, the measured PL spectra are featured by two sets of multi-mode vibronic luminescence lines. Based on the variable-temperature PL spectra and Raman spectra, the dual zero-phonon lines and the two sets of multimode vibronic lines with a constant energy separation of ∼2.8 meV are identified. This study leads to the unprecedented determination of the splitting energy of the 2Eg excited-state and the confirmation of multiple vibrational modes involved within the vibronic luminescence.

Excited-states play a crucial role in the optical absorption and luminescence of solids and hence their accurate information is highly desired. Herein, we attempt to seize the excited-states information of Mn4+ ions in K2SiF6 microcrystals via measuring and calculating their variable-temperature photoluminescence excitation (PLE) spectra. At cryogenic temperatures, an unpredicted splitting of the high-excited-state is observed. Moreover, the two-split high-excited-state levels are further revealed to primarily couple with the two hyperfine split modes of quasi-localized v2 vibration in the distorted Mn-F6 octahedral configuration, whereas the coupling strengths are found to be substantially different from each other. The slightly split vibrational mode is firmly supported by the low-temperature Raman spectra. Jahn-Teller lattice distortion is believed to be responsible for the observed splitting of the electronic high-excited-state and the quasi-localized vibrational mode.

DOI:10.1186/s11671-023-03818-4, Abstrct:

DOI:10.3390/s23136184, Abstrct:

DOI:10.1021/acsphotonics.3c00768, Abstrct:

In this paper, the giant tunability of thermal behaviors, i.e., from thermal deterioration to substantial growth, is firmly demonstrated for the vibronic luminescence of Mn4+ ions in fluoride phosphors. Such peculiar behavior is uncovered to be associated with the thermal excitation of a low-frequency phonon bath, and a theoretical model involving the excitation-wavelength-dependent populations of vibronic levels and the temperature-dependent nonradiative recombination processes is successfully constructed. Two main governing parameters, namely, the thermal activation energy Ea and the involved average phonon energy ΔE, are thus determined for the distinct thermal behaviors of Mn4+-ion luminescence. This demonstration may pave the way for manipulating the thermal behaviors of vibronic luminescence in solids to some extent.

DOI:10.1016/j.rinp.2022.105336, Abstrct:

DOI:10.1016/j.rinp.2022.105734, Abstrct:

DOI:10.1016/j.vacuum.2021.110822, Abstrct: A synergistic approach of interface engineering is reported to efficiently improve the performance of silicon nanocrystal light-emitting diode (Si-NC LED). This approach employs electron transport layer (ETL) of n-type gallium-nitride (n-GaN) and hole transport layer (HTL) of alumina (Al2O3) to improve the charge injection and transport during the electroluminescence (EL) excitation, and charge confinement layers (CCLs) of SiO2 and Al2O3 to confine the injected charges within the active layer to improve the radiative recombination. The ETL and HTL introduced in this work were found to be of superior function in enhancing the EL emission of Si-NCs LED, so did the CCLs. The synergistic application of the interface engineering, combined with the optimization of the active layer thickness, yielded an evident increase in the brightness of Si-NCs LED.

High-efficiency Mn4+-activated red phosphor of K2SIF6:Mn4+ synthesized at low temperature was utilized to fabricate phosphor-converted white light-emitting diodes (pc-WLEDs). Temperature-dependent electroluminescence (EL) measurements were undertaken at a constant forward voltage mode. A large negative-thermal-quenching (NTQ) effect is demonstrated for the luminescence intensity of this kind of red phosphor in the temperature range of 100-300 K. It is found that its enhancement rate is several times higher than those of the blue chip and the green component, such that the overall color of the pc-WLED shows a wide color gamut in the studied temperature range. By utilizing this outstanding NTQ property of the red phosphor, a color rendering index up to R-a = 93 is obtained for the high-brightness pc-WLED with relatively low blue light from the LED chip.

DOI:10.1016/j.physe.2021.114680, Abstrct:

DOI:10.1016/j.vacuum.2021.110183, Abstrct:

DOI:10.1364/PRJ.417866, Abstrct:

DOI:10.1016/j.cplett.2021.139155, Abstrct: Freestanding silicon nanocrystals (SiNCs) were prepared based on triethoxysilane (TES) by a series processes of chemistry and physics. To prevent self-aggregation, the freestanding SiNCs were mixed with 1-dodecene and mesitylene, followed by addition reaction in argon. A dispersed freestanding SiNC colloid was thus attained. A Si white light-emitting diode was fabricated using the dispersed freestanding SiNCs by mixing them with hydrogen silsesquioxane (HSQ) as the active layer. The electroluminescence emission of the device showed a continuous spectrum covering the whole visible regime in the white emission region of chromatic chart.

DOI:10.1109/JSTQE.2019.2918934, Abstrct: With the development of nanomanufacturing methods, the manipulation of photons down to the nanoscale in silicon integrated optical chips has become a feasible and promising solution for next-generation data processing as electronic chips reach their limit. As an essential active device that generates photons for all other working photonic components, silicon lasers are the last barrier to achieve silicon integrated optical chips. Although optical gain in silicon nanocrystals (Si-NCs) was observed in 2000, the progress in realizing all-Si lasers has been very limited due to the inferior optical gain compared to traditional gain materials. In this paper, highly luminescent thin films of Si-NCs with a photoluminescence quantum yield of 57% are developed. The broadband photoluminescence covers the wavelength range from 650 to 900 nm, and wide-range optical gains are identified, indicating the feasibility of a tunable laser. Distributed feedback (DFB) all-Si lasers are fabricated using these thin films and pumped by femtosecond pulses. Various characteristic lasing behaviors are observed. Additionally, three different DFB grating periods are selected, and the lasing peak can be tuned by over 100 nm. The lasing thresholds range from 83 to 53.3 MW/cm(2). The linewidths of lasing peaks are less than 2 nm.

DOI:10.1088/1674-1056/abb3e3, Abstrct: We report an approach of high-pressure hydrogenation to improve the performance of crystalline Si (c-Si) solar cells. As-received p-type c-Si wafer-based PN junctions were subjected to high-pressure (2.5 MPa) hydrogen atmosphere at 200 degrees C, followed by evaporating antireflection layers, passivation layers, and front and rear electrodes. The efficiency of the so prepared c-Si solar cell was found to increase evidently after high-pressure hydrogenation, with a maximal enhancement of 10%. The incorporation of hydrogen by Si solar cells was identified, and hydrogen passivation of dangling bonds in Si was confirmed. Compared to the regular approach of hydrogen plasma passivation, the approach of high-pressure hydrogenation reported here needs no post-hydrogenation treatment, and can be more convenient and efficient to use in improving the performances of the c-Si and other solar cells.

DOI:10.1364/OE.382691, Abstrct: With low toxicity and high abundance of silicon, silicon nanocrystal (Si-NC) based white light-emitting device (WLED) is expected to be an alternative promising choice for general lighting in a cost-effective and environmentally friendly manner. Therefore, an all-inorganic Si-NC based WLED was reported for the first time in this paper. The active layer was made by mixing freestanding Si-VCs with hydrogen silsesquioxane (HSQ), followed by annealing and preparing the carrier transport layer and electrodes to complete the fabrication of an LED. Under forward biased condition, the electroluminescence (EL) spectrum of the LED showed a broadband spectrum. It was attributed to the mechanism of differential passivation of Si-VCs. The performance of LED could be optimized by modifying the annealing temperature and ratio of Si-NCs to HSQ in the active layer. The external quantum efficiency (EQE) peak of the Si WLED was 1.0% with a corresponding luminance of 225.8 cd/m(2), and the onset voltage of the WLED was 2.9V. The chromaticity of the WLED indicated a warm white light emission. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

DOI:10.1364/OE.396654, Abstrct: High-density Si nanocrystal thin film composed of Si nanocrystals and SiO2, or SiNCs:SiO2, was prepared by annealing hydrogen silsesquioxane (HSQ) in a hydrogen and nitrogen (H-2:N-2=5%:95%) atmosphere at 1100 degrees C. Conventional normal-pressure (1-bar) hydrogenation failed to enhance the light emission of the Si-NCs:SiO2 sample made from HSQ. High-pressure hydrogenation was then applied to the sample in a 30-bar hydrogen atmosphere for this purpose. The light emission of Si-NCs increased steadily with increasing hydrogenation time. The photoluminescence (PL) intensity, the PL quantum yield, the maximal electroluminescence intensity, and the optical gain were increased by 90%, 114%, 193% and 77%, respectively, after 10-day high-pressure hydrogenation, with the PL quantum yield as high as 59 degrees 70, under the current experimental condition. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

DOI:10.1364/OE.27.003161, Abstrct: Sub-bandgap near-infrared silicon (Si) photodetectors are key elements in integrated Si photonics. We demonstrate such a Si photodetector based on a black Si (b-Si)/Ag nanoparticles (Ag-NPs) Schottky junction. This photodetector synergistically employs the mechanisms of inner photoemission, light-trapping, and surface-plasmon-enhanced absorption to efficiently absorb the sub-bandgap light and generate a photocurrent. The b-Si/Ag-NPs sample was prepared by means of wet chemical etching. Compared to those of a planar-Si/Ag thin-film Schottky photodetector, the responsivities of the b-Si/Ag-NPs photodetector were greatly enhanced, being 0.277 and 0.226 mA/W at a reversely biased voltage of 3 V for 1319- and 1550-nm light, respectively.

DOI:10.1016/j.scib.2018.01.006, Abstrct:

This book focuses on the optical characterization of wide band gap semiconductor micro-nano structures and advanced optoelectronic devices including GaN-based laser diodes, GaN-based micro-LEDs, ZnO-based micro-lasers, Ga2O3-based deep UV photodetectors, etc., written by leading scholars in the field from the perspective of applied research and development of advanced optoelectronic devices.

本书以宽禁带半导体微结构与光电器件光学表征为主线，按照“面向宽禁带半导体前沿课题，注重先进光电器件与材料微结构的基础性质和过程进行光学表征，以提升宽禁带半导体光电子器件性能为目的”的原则安排全书内容，从应用基础研究和研发先进光电子器件的角度出发，组织全国在该领域前沿进行一线科研工作的学者进行编写，力争用通俗易懂的语言，由浅入深，系统、详细地介绍宽禁带半导体光电器件微纳结构生长、掺杂、受激辐射、量子效率测量、紫外探测、微尺寸LED、高效太阳能电池等工作原理、光学表征、性能提升等前沿研究。本书可作为高等学校半导体光电子类相关专业高年级本科生和研究生的教材或教学参考书，也可作为相关科研工作者的学习参考书。