The open-circuit voltages of mature single-junction photovoltaic devices are lower than the bandgap energy of the absorber, typically by a gap of 400 mV. For CdTe, which has a bandgap of 1.5 eV, the gap is larger; for polycrystalline samples, the open-circuit voltage of solar cells with the record efficiency is below 900 mV, whereas for monocrystalline samples it has only recently achieved values barely above 1 V. Here, we report a monocrystalline CdTe/MgCdTe double-heterostructure solar cell with open-circuit voltages of up to 1.096 V. The latticed-matched MgCdTe barrier layers provide excellent passivation to the CdTe absorber, resulting in a carrier lifetime of 3.6 μs. The solar cells are made of 1- to 1.5-μm-thick n-type CdTe absorbers, and passivated hole-selective p-type a-SiCy:H contacts. This design allows CdTe solar cells to be made thinner and more efficient. The best power conversion efficiency achieved in a device with this structure is 17.0%.

Nature Energy Article number: 16067 (2016)
doi:10.1038/nenergy.2016.67

http://www.nature.com/articles/nenergy201667

成熟的单结太阳能器件开路电压通常为400mV。多晶CdTe的开路电压低于900mV,即使单晶CdTe的开路电压也很少有高于1V。目前美国亚利桑那州立大学的研究人员开发的CdTe/MgCdTe双异质结太阳能电池的开路电压达到1.096V。与CdTe晶格匹配的MgCdTe势垒层对CdTe吸收层提供了极好的钝化，从而使载流子寿命达到3.6us。他们设计的太阳能电池由1-1.5um厚的n型CdTe吸收层和钝化的p型a-SiCy：H接触组成。这一设计使得CdTe太阳能电池能够更薄、更有效，最好的功率转化效率达到了17.0%。（新材料在线）