Effect of Annealing on Performance of Solar Cells with New Oxide Absorber Mn$_2$V$_2$O$_7$

Abstract

All-oxide solar cells are attractive due to their stability, low cost and ease of fabrication. Very few oxide-absorbers are known and the efficiencies are limited by low mobility and lifetimes. In this work, for the first time, photovoltaic properties of a new oxide semiconductor, Mn2V2O7(MVO) are described. Optical measurements show that MVO has an indirect bandgap of 1.6 eV and a direct bandgap of 1.75 eV, which suggests that it absorbs efficiently in the visible region of the solar spectrum. The valence and conduction band positions of the intrinsically n-doped MVO film are determined to be at 5.5 eV and 3.9 eV. Schottky solar cells fabricated using Pt/MVO heterojunction show low short circuit current (JSC) and open circuit voltage (VOC). Annealing in nitrogen ambience results in a JSC of 0.46 mA/cm2a 50× increase and of VOC0.21 V, almost 10× increase compared to un-annealed device. A maximum power of 24.1 μW/cm2is obtained, which is two orders of magnitude higher than un-annealed devices.

Publication
2017 IEEE 44th Photovoltaic Specialist Conference (PVSC)
Date
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