利用分子束外延方法制备了应用于四结光伏电池的1.05 eV InGaAsP薄膜,并对其超快光学特性进行了研究.温度和激发功率有关的发光特性表明:InGaAsP材料以自由激子发光为主.室温下InGaAsP材料的载流子发光弛豫时间达到10.4 ns,且随激发功...利用分子束外延方法制备了应用于四结光伏电池的1.05 eV InGaAsP薄膜,并对其超快光学特性进行了研究.温度和激发功率有关的发光特性表明:InGaAsP材料以自由激子发光为主.室温下InGaAsP材料的载流子发光弛豫时间达到10.4 ns,且随激发功率增大而增大.发光弛豫时间随温度升高呈现S形变化,在低于50 K时随温度升高而增大,在50-150 K之间时减小,而温度高于150 K时再次增大.基于载流子弛豫动力学,分析并解释了温度及非辐射复合中心浓度对样品材料载流子发光弛豫时间S形变化的影响.展开更多
The internal behaviors of carriers in InGaAsP single-junction solar cell are investigated by using electroluminescence(EL) measurements. Two emission peaks can be observed in current-dependent electroluminescence spec...The internal behaviors of carriers in InGaAsP single-junction solar cell are investigated by using electroluminescence(EL) measurements. Two emission peaks can be observed in current-dependent electroluminescence spectra at low temperatures, and carrier localization exists for both peaks under low excitation. The trends of power index α extracted from excitation-dependent EL spectra at different temperatures imply that there exists a competition between Shockley–Read–Hall recombination and Auger recombination. Auger recombination becomes dominant at high temperatures, which is probably responsible for the lower current density of InGaAsP solar cell. Besides, the anomalous “S-shape” tendency with the temperature of band-edge peak position can be attributed to potential fluctuation and carrier redistribution, demonstrating delocalization, transfer, and redistribution of carriers in the continuum band-edge. Furthermore, the strong reduction of activation energy at high excitations indicates that electrons and holes escaped independently, and the faster-escaping carriers are holes.展开更多
Due to the wide application of UV-A(320 nm–400 nm)and UV-C(200 nm–280 nm)photodetectors,dual-wavelength(UV-A/UV-C)photodetectors are promising for future markets.A dual-wavelength UV photodetector based on vertical(...Due to the wide application of UV-A(320 nm–400 nm)and UV-C(200 nm–280 nm)photodetectors,dual-wavelength(UV-A/UV-C)photodetectors are promising for future markets.A dual-wavelength UV photodetector based on vertical(Al,Ga)N nanowires and graphene has been demonstrated successfully,in which graphene is used as a transparent electrode.Both UV-A and UV-C responses can be clearly detected by the device,and the rejection ratio(R254 nm/R450 nm)exceeds35 times at an applied bias of-2 V.The short response time of the device is less than 20 ms.Furthermore,the underlying mechanism of double ultraviolet responses has also been analyzed systematically.The dual-wavelength detections could mainly result from the appropriate ratio of the thicknesses and the enough energy band difference of(Al,Ga)N and Ga N sections.展开更多
The application of transparent conducting indium-tin-oxide （ITO） film as full front electrode replacing the conven- tional bus-bar metal electrode in III-V compound GalnP solar cell was proposed. A high-quality, non...The application of transparent conducting indium-tin-oxide （ITO） film as full front electrode replacing the conven- tional bus-bar metal electrode in III-V compound GalnP solar cell was proposed. A high-quality, non-rectifying contact between ITO and 10 nm N＋-GaAs contact layer was formed, which is benefiting from a high carrier concentration of the terrilium-doped N＋-GaAs layer, up to 2×10^19 cm^-3. A good device performance of the GalnP solar cell with the ITO electrode was observed. This result indicates a great potential of transparent conducting films in the future fabrication of larger area flexible III-V solar cell.展开更多
InGaN/GaN epilayers, which are grown on sapphire substrates by the metal-organic chemical-vapour deposition （MOCVD） method, are formed into nanorod arrays using inductively coupled plasma etching via self-assembled ...InGaN/GaN epilayers, which are grown on sapphire substrates by the metal-organic chemical-vapour deposition （MOCVD） method, are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks. The formation of nanorod arrays eliminates the tilt of the InGaN （0002） crystallographic plane with respect to its GaN bulk layer. Photoluminescence results show an apparent S-shaped dependence on temperature. The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area, which increases the quenching effect because of the high density of surface states for the temperature above 30 K. Additionally, a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation, which is confirmed by reciprocal space mapping measurements.展开更多
We report InGaN/GaN multi-quantum well (MQW) solar cells with a comparatively high open-circuit voltage and good concentration properties.Thc open circuit voltage (Voc) keeps increasing logarithmically with concentrat...We report InGaN/GaN multi-quantum well (MQW) solar cells with a comparatively high open-circuit voltage and good concentration properties.Thc open circuit voltage (Voc) keeps increasing logarithmically with concentration ratio until 60suns.The peak Voc of InGaN/GaN MQW solar cells,which has a predominant peak wavelength of 456nm from electroluminescence measurements,is found to be 2.45 V when the concentration ratio reaches 333×.Furthermore,the dcpendence of conversion efficiency and fill factor on concentration ratio are analyzed.展开更多
基金Supported by the National High Technology Research and Development Program of China(2018YFB2003305)the Key R&D Program of Jiangsu Province(BE2018005)+2 种基金the Science and Technology Service Network Initiative of the Chinese Academy of Sciences(KFJ-STS-ZDTP-086)the Support From SINANO(Y8AAQ11003)Natural Science Foundation of Jiangsu Province(BK20180252)。
基金Project supported by the National Key Research and Development Program,China (Grant No.2018YFB2003305)the National Natural Science Foundation of China (Grant Nos.61774165 and 61827823)the Key Laboratory Fund in Suzhou Institute of Suzhou Nano-Tech and NanoBionis (SINANO),Chinese Academy of Sciences (Grant No.Y4JAQ21005)。
文摘The internal behaviors of carriers in InGaAsP single-junction solar cell are investigated by using electroluminescence(EL) measurements. Two emission peaks can be observed in current-dependent electroluminescence spectra at low temperatures, and carrier localization exists for both peaks under low excitation. The trends of power index α extracted from excitation-dependent EL spectra at different temperatures imply that there exists a competition between Shockley–Read–Hall recombination and Auger recombination. Auger recombination becomes dominant at high temperatures, which is probably responsible for the lower current density of InGaAsP solar cell. Besides, the anomalous “S-shape” tendency with the temperature of band-edge peak position can be attributed to potential fluctuation and carrier redistribution, demonstrating delocalization, transfer, and redistribution of carriers in the continuum band-edge. Furthermore, the strong reduction of activation energy at high excitations indicates that electrons and holes escaped independently, and the faster-escaping carriers are holes.
基金the National Key Research and Development Program of China(Grant No.2018YFB0406602)Natural Science Foundation of Jiangsu Province,China(Grant No.BK20180252)+6 种基金Key Research Program of Frontier Sciences,CAS(Grant No.ZDBS-LY-JSC034)the National Natural Science Foundation of China(Grant Nos.61804163,61875224,and 61827823)the Key Research and Development Program of Jiangsu Province,China(Grant No.BE2018005)Natural Science Foundation of Jiangxi Province,China(Grant No.20192BBEL50033)Research Program of Scientific Instrument,Equipment of CAS(Grant No.YJKYYQ20200073)SINANO(Grant Nos.Y8AAQ21001 and Y4JAQ21001)Vacuum Interconnected Nanotech Workstation(Grant Nos.Nano-X and B2006)。
文摘Due to the wide application of UV-A(320 nm–400 nm)and UV-C(200 nm–280 nm)photodetectors,dual-wavelength(UV-A/UV-C)photodetectors are promising for future markets.A dual-wavelength UV photodetector based on vertical(Al,Ga)N nanowires and graphene has been demonstrated successfully,in which graphene is used as a transparent electrode.Both UV-A and UV-C responses can be clearly detected by the device,and the rejection ratio(R254 nm/R450 nm)exceeds35 times at an applied bias of-2 V.The short response time of the device is less than 20 ms.Furthermore,the underlying mechanism of double ultraviolet responses has also been analyzed systematically.The dual-wavelength detections could mainly result from the appropriate ratio of the thicknesses and the enough energy band difference of(Al,Ga)N and Ga N sections.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61534008,61376081,and 61404157)the Application Foundation of Suzhou,China(Grant No.SYG201437)
文摘The application of transparent conducting indium-tin-oxide （ITO） film as full front electrode replacing the conven- tional bus-bar metal electrode in III-V compound GalnP solar cell was proposed. A high-quality, non-rectifying contact between ITO and 10 nm N＋-GaAs contact layer was formed, which is benefiting from a high carrier concentration of the terrilium-doped N＋-GaAs layer, up to 2×10^19 cm^-3. A good device performance of the GalnP solar cell with the ITO electrode was observed. This result indicates a great potential of transparent conducting films in the future fabrication of larger area flexible III-V solar cell.
基金Project supported by the SONY-SINANO Joint Project (Grant No. Y1AAQ11001)the Suzhou Solar Cell Research Project,China (Grant No. ZXJ0903)+1 种基金the International S & T Cooperation Projects (SINO-Japan)the Science Fund of the Ministry of Science and Technology of the People’s Republic of China (Grant No. 2010DFA22770)
文摘InGaN/GaN epilayers, which are grown on sapphire substrates by the metal-organic chemical-vapour deposition （MOCVD） method, are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks. The formation of nanorod arrays eliminates the tilt of the InGaN （0002） crystallographic plane with respect to its GaN bulk layer. Photoluminescence results show an apparent S-shaped dependence on temperature. The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area, which increases the quenching effect because of the high density of surface states for the temperature above 30 K. Additionally, a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation, which is confirmed by reciprocal space mapping measurements.
基金Supported by the Joint Projects under Grant Nos Y1AAQ11001 and Y1EAQ31001the Suzhou Solar Cell Research Project under Grant No ZXJ0903the Ministry of Science and Technology of China under Grant No 2010DFA22770.
文摘We report InGaN/GaN multi-quantum well (MQW) solar cells with a comparatively high open-circuit voltage and good concentration properties.Thc open circuit voltage (Voc) keeps increasing logarithmically with concentration ratio until 60suns.The peak Voc of InGaN/GaN MQW solar cells,which has a predominant peak wavelength of 456nm from electroluminescence measurements,is found to be 2.45 V when the concentration ratio reaches 333×.Furthermore,the dcpendence of conversion efficiency and fill factor on concentration ratio are analyzed.
