Theoretical efficiency of SnO2/Si solar cells

At present SnO2/Si solar cells with efficiencies greater than 12% have been fabricated. The maximum theoretical efficiency attainable with such cells is of great interest and is reported in the present paper. The cells behave very much like MIS devices. The insulating oxide and surface density of states at the interface affect the performance of the device mainly through the diode constant and the barrier height φB. The theoretical maximum short-circuit photocurrent, the open-circuit photovoltage, and the fill factor are 36 mA/cm2, 0.66 V, and 0.84, respectively. They yield a maximum theoretical efficiency of 20%.