We report a GaInP/GaAs tandem solar cell with a novel GaAs tunnel junction（TJ） with using tellurium（Te） and magnesium（Mg） as n- and p-type dopants via dual-filament low temperature effusion cells grown by molecu...We report a GaInP/GaAs tandem solar cell with a novel GaAs tunnel junction（TJ） with using tellurium（Te） and magnesium（Mg） as n- and p-type dopants via dual-filament low temperature effusion cells grown by molecular beam epitaxy（MBE） at low temperature. The test Te/Mg-doped GaAs TJ shows a peak current density of 21 A/cm2. The tandem solar cell by the Te/Mg TJ shows a short-circuit current density of 12 m A/cm2, but a low open-circuit voltage range of1.4 V^1.71 V under AM1.5 illumination. The secondary ion mass spectroscopy（SIMS） analysis reveals that the Te doping is unexpectedly high and its doping profile extends to the Mg doping region, thus possibly resulting in a less abrupt junction with no tunneling carriers effectively. Furthermore, the tunneling interface shifts from the intended Ga As n＋＋/p＋＋junction to the AlGaInP/GaAs junction with a higher bandgap AlGaInP tunneling layers, thereby reducing the tunneling peak. The Te concentration of ~ 2.5 × 1020 in GaAs could cause a lattice strain of 10-3 in magnitude and thus a surface roughening,which also negatively influences the subsequent growth of the top subcell and the GaAs contacting layers. The doping features of Te and Mg are discussed to understand the photovoltaic response of the studied tandem cell.展开更多
The Ⅲ-Ⅴ compound tandem solar cell is a third-generation new style solar cell with ultra-high efficiency. The energy band gaps of the sub-cells in a GaInP/GaAs/InGaAs/Ge 4-J tandem solar cell are 1.8, 1.4, 1.0 and ...The Ⅲ-Ⅴ compound tandem solar cell is a third-generation new style solar cell with ultra-high efficiency. The energy band gaps of the sub-cells in a GaInP/GaAs/InGaAs/Ge 4-J tandem solar cell are 1.8, 1.4, 1.0 and 0.7 eV, respectively. In order to match the currents between sub-cells, tunnel junctions are used to connect the sub-cells. The characteristics of the tunnel junction, the material used in the tunnel junction, the compensation of the tunnel junction to the overall cell＇s characteristics, the tunnel junction＇s influence on the current density of sub-cells and the efficiency increase are discussed in the paper. An A1GaAs/GaAs tunnel junction is selected to simulate the cell＇s overall characteristics by PC 1 D, current densities of 16.02, 17.12, 17.75 and 17.45 mA/cm^2 are observed, with a Voc of 3.246 V, the energy conversion efficiency under AM0 is 33.9%.展开更多
Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in preci...Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in precisely controlling the inter-subcells carrier migration which determines the balance of charge transport across the entire device.The conductivity of"nanowires"-like conducting channel in interconnecting layer between sub-cells should be improved which calls for fine engineering on the morphology of polyelectrolyte in interconnecting layer.Here,we develop a simple method to effectively manipulating the domains of conductive components in commercially available polyelectrolyte PEDOT:PSs.The use of poor solvent could effectively modify the configuration of polystyrene sulfonic acid and thus the space for conductive components.Based on our strategy,the insulated shells wrapping conductive domains are thinned and the efficiencies of tandem organic solar cells are improved.We believe our method might provide guidance for the manufacture of tandem organic solar cells.展开更多
基金Project supported by the SINANO-SONY Joint Program(Grant No.Y1AAQ11001)the National Natural Science Foundation of China(Grant No.61274134)+1 种基金the USCB Start-up Program(Grant No.06105033)the International Cooperation Projects of Suzhou City,China(Grant No.SH201215)
文摘We report a GaInP/GaAs tandem solar cell with a novel GaAs tunnel junction（TJ） with using tellurium（Te） and magnesium（Mg） as n- and p-type dopants via dual-filament low temperature effusion cells grown by molecular beam epitaxy（MBE） at low temperature. The test Te/Mg-doped GaAs TJ shows a peak current density of 21 A/cm2. The tandem solar cell by the Te/Mg TJ shows a short-circuit current density of 12 m A/cm2, but a low open-circuit voltage range of1.4 V^1.71 V under AM1.5 illumination. The secondary ion mass spectroscopy（SIMS） analysis reveals that the Te doping is unexpectedly high and its doping profile extends to the Mg doping region, thus possibly resulting in a less abrupt junction with no tunneling carriers effectively. Furthermore, the tunneling interface shifts from the intended Ga As n＋＋/p＋＋junction to the AlGaInP/GaAs junction with a higher bandgap AlGaInP tunneling layers, thereby reducing the tunneling peak. The Te concentration of ~ 2.5 × 1020 in GaAs could cause a lattice strain of 10-3 in magnitude and thus a surface roughening,which also negatively influences the subsequent growth of the top subcell and the GaAs contacting layers. The doping features of Te and Mg are discussed to understand the photovoltaic response of the studied tandem cell.
基金supported by the National Natural Science Foundation of China(No.10778723)
文摘The Ⅲ-Ⅴ compound tandem solar cell is a third-generation new style solar cell with ultra-high efficiency. The energy band gaps of the sub-cells in a GaInP/GaAs/InGaAs/Ge 4-J tandem solar cell are 1.8, 1.4, 1.0 and 0.7 eV, respectively. In order to match the currents between sub-cells, tunnel junctions are used to connect the sub-cells. The characteristics of the tunnel junction, the material used in the tunnel junction, the compensation of the tunnel junction to the overall cell＇s characteristics, the tunnel junction＇s influence on the current density of sub-cells and the efficiency increase are discussed in the paper. An A1GaAs/GaAs tunnel junction is selected to simulate the cell＇s overall characteristics by PC 1 D, current densities of 16.02, 17.12, 17.75 and 17.45 mA/cm^2 are observed, with a Voc of 3.246 V, the energy conversion efficiency under AM0 is 33.9%.
基金the National Natural Science Foundation of China(NSFC)(22275016,21835006,22122905)Beijing Municipal Science&Technology Commission(2232078)+2 种基金Beijing National Laboratory for Molecular Sciences(BNLMS)Junior Fellow(2019BMS20014,BNLMS-CXXM-201903)National Research Council of Science and Technology of Korea(Global20-004)the Key Research Program of the Chinese Academy of Sciences(XDPB13-3).
文摘Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in precisely controlling the inter-subcells carrier migration which determines the balance of charge transport across the entire device.The conductivity of"nanowires"-like conducting channel in interconnecting layer between sub-cells should be improved which calls for fine engineering on the morphology of polyelectrolyte in interconnecting layer.Here,we develop a simple method to effectively manipulating the domains of conductive components in commercially available polyelectrolyte PEDOT:PSs.The use of poor solvent could effectively modify the configuration of polystyrene sulfonic acid and thus the space for conductive components.Based on our strategy,the insulated shells wrapping conductive domains are thinned and the efficiencies of tandem organic solar cells are improved.We believe our method might provide guidance for the manufacture of tandem organic solar cells.
