Yellow light-emitting diodes(LEDs) are widely utilized in high-quality lighting, light communication,indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovs...Yellow light-emitting diodes(LEDs) are widely utilized in high-quality lighting, light communication,indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovskites have demonstrated a significant potential for LED applications. However, the performance of the yellow perovskite LEDs(PeLEDs) is inferior to that of their green and red counterparts, with the maximum external quantum efficiency(EQE) limited to ~3.1%. Further, a majority of the yellow PeLEDs are fabricated using the spin-coating methods. The current study reports the development of the yellow CsPbBr_(2)I PeLEDs based on an all-vacuum deposition approach, which has been widely employed in the commercial organic LEDs(OLEDs). By controlling the co-evaporation rate of CsI and PbBr;, the growth kinetics of the perovskite layer are regulated to achieve a small grain size of~31.8 nm. Consequently, an improved radiative recombination rate(8.04 × 10^(-9)cm^(3)/s) is obtained owing to the spatial confinement effect. The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence(574 nm) with a maximum EQE of ~3.7% and luminance of~16,200 cd/m^(2), thus, representing one of the most efficient and bright yellow PeLEDs. Overall, this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.展开更多
Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrow...Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.展开更多
Cadmium selenide(CdSe)belongs to the binary II-VI group semiconductor with a direct bandgap of~1.7 eV.The suitable bandgap,high stability,and low manufacturing cost make CdSe an extraordinary candidate as the top cell...Cadmium selenide(CdSe)belongs to the binary II-VI group semiconductor with a direct bandgap of~1.7 eV.The suitable bandgap,high stability,and low manufacturing cost make CdSe an extraordinary candidate as the top cell material in silicon-based tandem solar cells.However,only a few studies have focused on CdSe thin-film solar cells in the past decades.With the advantages of a high deposition rate(~2µm/min)and high uniformity,rapid thermal evaporation(RTE)was used to maximize the use efficiency of CdSe source material.A stable and pure hexagonal phase CdSe thin film with a large grain size was achieved.The CdSe film demonstrated a 1.72 eV bandgap,narrow photoluminescence peak,and fast photoresponse.With the optimal device structure and film thickness,we finally achieved a preliminary efficiency of 1.88%for CdSe thin-film solar cells,suggesting the applicability of CdSe thin-film solar cells.展开更多
基金supported by the National Natural Science Foundation of China(62050039 61725401 5171101030 51761145048 62004075 62005089 and 51902113)the National Key R&D Program of China(2016YFA0204000 and 2016YFB0201204)+2 种基金the Fundamental Research Funds for the Central Universities(HUST: 2019421JYCXJJ004)the Fund for Innovative Research Groups of the Natural Science Foundation of Hubei Province(2020CFA034)the Graduates’ Innovation Fund of Huazhong University of Science and Technology(HUST)(2021yjscxcy036)。
文摘Yellow light-emitting diodes(LEDs) are widely utilized in high-quality lighting, light communication,indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovskites have demonstrated a significant potential for LED applications. However, the performance of the yellow perovskite LEDs(PeLEDs) is inferior to that of their green and red counterparts, with the maximum external quantum efficiency(EQE) limited to ~3.1%. Further, a majority of the yellow PeLEDs are fabricated using the spin-coating methods. The current study reports the development of the yellow CsPbBr_(2)I PeLEDs based on an all-vacuum deposition approach, which has been widely employed in the commercial organic LEDs(OLEDs). By controlling the co-evaporation rate of CsI and PbBr;, the growth kinetics of the perovskite layer are regulated to achieve a small grain size of~31.8 nm. Consequently, an improved radiative recombination rate(8.04 × 10^(-9)cm^(3)/s) is obtained owing to the spatial confinement effect. The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence(574 nm) with a maximum EQE of ~3.7% and luminance of~16,200 cd/m^(2), thus, representing one of the most efficient and bright yellow PeLEDs. Overall, this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.
基金China Postdoctoral Science Foundation Project,Grant/Award Numbers:2020M680101,2021T140233Fundamental Research Funds for the Central Universities,Grant/Award Number:2021XXJS028+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:61725401,61904058,62050039the Graduates'Innovation Fund of Huazhong University of Science and Technology,Grant/Award Number:2021yjsCXCY051the National Key R&D Program of China,Grant/Award Number:2016YFA0204000。
文摘Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.
基金the National NaturalScience Foundation of China (Grant Nos. 61725401, 61904058,and 62050039)the National Key R&D Program of China (No.2016YFA0204000)+2 种基金the Innovation Fund of WNLO, National PostdoctoralProgram for Innovative Talent (No. BX20190127)the Graduates’ InnovationFund of Huazhong University of Science and Technology (No.2020yjsCXCY003)China Postdoctoral Science Foundation Project(Nos. 2019M662623 and 2020M680101).
文摘Cadmium selenide(CdSe)belongs to the binary II-VI group semiconductor with a direct bandgap of~1.7 eV.The suitable bandgap,high stability,and low manufacturing cost make CdSe an extraordinary candidate as the top cell material in silicon-based tandem solar cells.However,only a few studies have focused on CdSe thin-film solar cells in the past decades.With the advantages of a high deposition rate(~2µm/min)and high uniformity,rapid thermal evaporation(RTE)was used to maximize the use efficiency of CdSe source material.A stable and pure hexagonal phase CdSe thin film with a large grain size was achieved.The CdSe film demonstrated a 1.72 eV bandgap,narrow photoluminescence peak,and fast photoresponse.With the optimal device structure and film thickness,we finally achieved a preliminary efficiency of 1.88%for CdSe thin-film solar cells,suggesting the applicability of CdSe thin-film solar cells.
