Effect Of Annealing On Performance Of Solar Cells With New Oxide Absorber Mn2v2o7

All-oxide solar cells are attractive due to their stability, low cost and ease of fabrication. Very few oxideabsorbers 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/cm(2) a 50x increase and of Voc 0.21 V, almost 10x increase compared to un-annealed device. A maximum power of 24.1 mu W/cm(2) is obtained, which is two orders of magnitude higher than un-annealed devices.