Strong Enhancement of Solar Cell Efficiency Due to Quantum Dots with Built-In Charge
journal contributionposted on 08.06.2011, 00:00 by Kimberly A. Sablon, John W. Little, Vladimir Mitin, Andrei Sergeev, Nizami Vagidov, Kitt Reinhardt
We report a 50% increase in the power conversion efficiency of InAs/GaAs quantum dot solar cells due to n-doping of the interdot space. The n-doped device was compared with GaAs reference cell, undoped, and p-doped devices. We found that the quantum dots with built-in charge (Q-BIC) enhance electron intersubband quantum dot transitions, suppress fast electron capture processes, and preclude deterioration of the open circuit voltage in the n-doped structures. These factors lead to enhanced harvesting and efficient conversion of IR energy in the Q-BIC solar cells.