Tunneling effects on temperature-dependent photocurrent intensity in InxGa1-xAs multiple-quantum-well diodes

Temperature dependence of the photocurrent (PC) intensity has been experimentally investigated as a function of reverse bias in high quality In
_0.1
Ga
_0.9
As/A
_0.15
Ga
_0.85
As multiple quantum wells (MQW) in a p-i-n diode configuration. PC features show unusual behaviors at low temperatures, especially at 15 K, such as (1) the PC intensity increase with the electric field under low field conditions at 15 K and (2) a reduction up to 60 K and a rise above 60 K, while the PC intensity under high field conditions decreases with temperature. These unusual PC features under low field conditions at low temperatures are explained by considering exciton ionization, the thermal population and the tunneling probability.