The p-GaAs/n-InP heterojunction was fabricated by direct wafer bonding technology. The optimized atomic level contact between GaAs and InP is critical for getting good ohmic contact and removing the bubbles or voids a...The p-GaAs/n-InP heterojunction was fabricated by direct wafer bonding technology. The optimized atomic level contact between GaAs and InP is critical for getting good ohmic contact and removing the bubbles or voids at the interface, which is helpful to enhance the efficiency of wafer bonded multi-junction solar cells. Through the surface megasonic cleaning and the plasma treatment, we have achieved the high quality bonding interface without bubbles or voids and with interface resistivity of about 0.1 ohms/cm^2. A GaInP/GaAs//InGaAsP/InGaAs 4-junction solar cell was prepared with the high efficiency of 34.4%(AM0)at 1 sun.展开更多
GaInP and AlGaInP solar cells were grown by metal organic chemical vapor deposition（MOCVD）, and theoretical analysis demonstrated that hetero-interface recombination velocity plays an important role in the optimizin...GaInP and AlGaInP solar cells were grown by metal organic chemical vapor deposition（MOCVD）, and theoretical analysis demonstrated that hetero-interface recombination velocity plays an important role in the optimizing of cell performance, especially the interface between base layer and back surface field（BSF）. Measurements including lattice-matched growth and pseudo-BSF were taken to optimize BSF design. Significant improvement of Vocin GaInP and AlGaInP solar cells imply that the measures we took are effective and promising for performance improvement in the next generation high efficiency solar cells.展开更多
Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things.The proposal of a d...Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things.The proposal of a dynamic heterojunction-based direct current generator builds up new platforms for developing in situ energy.However,the requirement of different semiconductors in dynamic heterojunction is too complex to wide applications,generating energy loss for crystal structure mismatch.Herein,dynamic homojunction generators are explored,with the same semiconductor and majority carrier type.Systematic experiments reveal that the majority of carrier directional separation originates from the breaking symmetry between carrier distribution,leading to the rebounding effect of carriers by the interfacial electric field.Strikingly,NN Si homojunction with different Fermi levels can also output the electricity with higher current density than PP/PN homojunction,attributing to higher carrier mobility.The current density is as high as 214.0 A/m^(2),and internal impedance is as low as 3.6 kΩ,matching well with the impedance of electron components.Furthermore,the N-i-N structure is explored,whose output voltage can be further improved to 1.3V in the case of the N-Si/Al2O3/N-Si structure,attributing to the enhanced interfacial barrier.This approach provides a simple and feasible way of converting low-frequency disordered mechanical motion into electricity.展开更多
基金supported by the Shanghai Rising-Star Program (No. 14QB1402800)
文摘The p-GaAs/n-InP heterojunction was fabricated by direct wafer bonding technology. The optimized atomic level contact between GaAs and InP is critical for getting good ohmic contact and removing the bubbles or voids at the interface, which is helpful to enhance the efficiency of wafer bonded multi-junction solar cells. Through the surface megasonic cleaning and the plasma treatment, we have achieved the high quality bonding interface without bubbles or voids and with interface resistivity of about 0.1 ohms/cm^2. A GaInP/GaAs//InGaAsP/InGaAs 4-junction solar cell was prepared with the high efficiency of 34.4%(AM0)at 1 sun.
基金Project supported by the National Natural Science Foundation of China (No. 61474076)
文摘GaInP and AlGaInP solar cells were grown by metal organic chemical vapor deposition（MOCVD）, and theoretical analysis demonstrated that hetero-interface recombination velocity plays an important role in the optimizing of cell performance, especially the interface between base layer and back surface field（BSF）. Measurements including lattice-matched growth and pseudo-BSF were taken to optimize BSF design. Significant improvement of Vocin GaInP and AlGaInP solar cells imply that the measures we took are effective and promising for performance improvement in the next generation high efficiency solar cells.
基金This work was funded by the National Natural Science Foundation of China(Nos.51202216,51502264,and 61774135)Special Foundation of Young Professor of Zhejiang University(No.2013QNA5007)Y.Wen thanks the support from the Science and Technology Project of Jiangsu Province Special Equipment Safety Supervision and Inspection Institute(KJY2017016).
文摘Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things.The proposal of a dynamic heterojunction-based direct current generator builds up new platforms for developing in situ energy.However,the requirement of different semiconductors in dynamic heterojunction is too complex to wide applications,generating energy loss for crystal structure mismatch.Herein,dynamic homojunction generators are explored,with the same semiconductor and majority carrier type.Systematic experiments reveal that the majority of carrier directional separation originates from the breaking symmetry between carrier distribution,leading to the rebounding effect of carriers by the interfacial electric field.Strikingly,NN Si homojunction with different Fermi levels can also output the electricity with higher current density than PP/PN homojunction,attributing to higher carrier mobility.The current density is as high as 214.0 A/m^(2),and internal impedance is as low as 3.6 kΩ,matching well with the impedance of electron components.Furthermore,the N-i-N structure is explored,whose output voltage can be further improved to 1.3V in the case of the N-Si/Al2O3/N-Si structure,attributing to the enhanced interfacial barrier.This approach provides a simple and feasible way of converting low-frequency disordered mechanical motion into electricity.
