Pulse laser deposition fabricated InP/Al-ZnO heterojunction solar cells with efficiency enhanced by an i-ZnO interlayer
Qiong Nian, Kyle H. Montgomery, Xin Zhao, Thomas N. Jackson, Jerry M. Woodall, and Gary J. Cheng
Applied Physics A, Sept. 2015.
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Indium phosphide (InP) has long since been seen as the ideal material choice for single-junction solar cells given its optimal band gap and high absorption coefficient. We report on the performance of heterojunction solar cells formed by depositing aluminum-doped ZnO (AZO), using pulsed laser deposition for the first time, onto p-type InP substrates. It is also found that a ZnO insulator layer (i-ZnO) between an InP base and AZO emitter can yield higher solar conversion efficiency and quantum efficiency over a baseline AZO/InP device. This 10-nm-thick intrinsic ultra-thin buffer enhanced collection probability but decreased surface recombination rate, which in turn shoot short-circuit current, open-circuit voltage, and fill factor to 17.4 mA/cm2, 0.58 V, and 72.9 %, respectively. A maximum power conversion efficiency of 7.3 % was realized by intergrading i-ZnO, which is ~20 % higher than baseline AZO/InP device of 6.1 %. This is also the record for this type of cell structure, using AZO as the emitter.
Indium phosphide, Photovoltaic cells, Solar energy, Zinc Oxide, Pulsed Laser Deposition
Q. Nian, K. H. Montgomery, X. Zhao, T. Jackson, J. M. Woodall, and G. J. Cheng, “Pulse laser deposition fabricated InP/Al-ZnO heterojunction solar cells with efficiency enhanced by an i-ZnO interlayer,” Appl. Phys. A, pp. 1–8, Sep. 2015.