根据 Shockley-Quisser模型，带隙能量为1.9/1.4/1.0/0.67 eV的多结太阳电池可以满足对太阳光谱高效吸收，实现太阳能电池的高电压、低电流输出，同时该结构可以有效降低高倍聚光太阳电池中的电阻热损失，从而降低高倍聚光电池的使用成本。但目前通过生长直接得到满足此带隙组合的高质量多结太阳能电池仍存在很多问题。该项目针对其材料生长和器件制备的两个关键点，通过分渐变以及应变超晶格作为缓冲结构在GaAs衬底上实现高质量的GaInP/GaAs/InGaAs三结太阳能电池，并利用晶片键合技术工艺，探索解决关键制备问题，实现此三结电池与Ge电池的单片集成，得到带隙能量为1.9/1.4/1.0/0.67 eV的多结太阳电池，该电池在理论上可以获得超过 45%的转换效率。通过该项目实施所获得的技术突破将有助于推动高效太阳能电池的进一步发展。

According to Shockley-Quisser theory, multi-Junction GaInP/GaAs/InGaAs/Ge solar cell with bandgap energy of 1.9/1.4/1.0/0.67 eV is a best choice for full-spectrum absorption of solar energy, which could get the output of high voltage and low current, and reduce the resistive heat loss in the high power concentrator solar cells. In order to overcome the difficulties of high quality materials growth in this system, we explore a new method to get multi-junction solar cells by bonding based on the GaInP/GaAs/InGaAs grown by all solid-state molecular-beam-epitaxy (MBE) technique. The aim of this project is to explore the high quality material growth technology with components gradient technology and strain superlattices as the buffer layer on GaAs based GaInP/GaAs/InGaAs triple junction. By exploring the high-quality wafer bonding technology, the monolithic integration of three-junction cells with Ge will be achieved. In theory this multi-junction structure could access the conversion efficiency of more than 45%. The result of this investigation will certainly provide a viable solution to the development of multi-junction solar cells.