Fabrication of InP/InGaAs/InP Double Heterojunction Solar Cell

• Main Authors: Sheng-Ying Wu, 吳昇穎
• Other Authors: Chih-Hung Wu
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/beepwb

碩士 === 國立臺北科技大學 === 光電工程系研究所 === 95 === 　　High-efficiency solar cells are desired for many applications such as Space, Transportation, Pocket Energy, Building, etc... InP-based solar cells are promising because of their high conversion efficiency and excellent anti-radiation ability. In this study, InP/InGaAs/InP double heterojunction (DH) solar cell was fabricated and characterization. 　　We have obtained a low resistivity ohmic contact system for InP. The lowest specific contact resistivity of n-metal and p-metal on InP were optimum by rapid thermal annealing (RTA) process and measured by transfer length method (TLM). The lowest value of specific contact resistivity of Ni/Ge/Au/Ni/Au for n-InP was 9.85×10-7 Ω•cm2 at 350 ˚C for 180 seconds under pure H2 atmosphere. Similarly, we have also achieved an extremely low specific contact resistivity of 2.24×10-5 Ω•cm2 of AuBe/Cr/Au for p-InP at 410 ˚C for 30 seconds in an air gas ambient. 　　The solar cell chips were 4×4 mm2 in size and had a 14 mm2 effective photosensitive area for sunlight absorbing with a 750 Å Si3N4 antireflection coating. All completed cells were tested under AM1.5 conditions. The I-V characteristics showed that the short-circuit current, open-circuit voltage, and the conversion efficiency could be significantly improved by decreasing the InP window layer thickness. Finally, a high efficiency of 10.35% p-on-n InP/InGaAs/InP DH solar cell was obtained; the corresponding short-circuit current density, open-circuit voltage, and fill factor were 43.133 mA/cm2, 0.385 V, 0.543, respectively.