On the photovoltaic response of Ge quantum dots in the intrinsic region of a Si p-i-n diode

It is demonstrated that a multilayer structure of Ge quantum dots deposited on Si spacer layers in the intrinsic region of a Si p-i-n diode exhibits a strong photovoltaic response in the infrared region. A Ge/Si active layer with a total thickness of 300 nm is found to provide an open-circuit voltage of about 0.6 V and short-circuit current of 24 mA cm−2 corresponding to an energy conversion efficiency of 11.5%.