Electrochemically deposited p–n homojunction cuprous oxide solar cells

The electrical properties of both p- and n-type cuprous oxide (Cu2O) films electrochemically deposited from two electrolyte solutions were examined by current–voltage measurements. The resistivity of p-type Cu2O varied from 3.2×105 to 2.0×108 Ω cm, while that of n-type Cu2O from 2.5×107 to 8.0×108 Ω cm, depending on deposition conditions such as solution pH, deposition potential and temperature. With optimized deposition conditions for minimum resistivity, p–n homojunction Cu2O solar cells were fabricated by a two-step deposition process. The p–n homojunction Cu2O solar cells showed a conversion efficiency of 0.1% under AM1 illumination. The low efficiency is attributed to the high resistivity of p- and n-type Cu2O, which require doping to reduce.