A Comprehensive Study on a Stand-Alone Germanium (Ge) Solar Cell

The effect of temperature on the performance parameters [short-circuit current density (J_SC), open-circuit voltage (V_OC), fill factor (FF), and conversion efficiency (η)] of stand-alone germanium (Ge) solar cells has been theoretically investigated. Although J_SC increased with increasing temperature, η decreased due to a decrease in V_OC and the associated decrease in the FF. The performance parameters J_SC, V_OC, FF, and η of a fabricated stand-alone Ge solar cell were determined from current-voltage (I-V) measurements. The significant differences between the obtained theoretical and experimental data may be related to both the use of idealized cases in the theoretical studies and the loss mechanisms considered to adversely affect the performance of the fabricated stand-alone Ge solar cell.