Non-pn-junction-based Solar Cells: Charge Carrier Separation in Solar Cells with Bound Surface Charges

Traditional junction-based solar cells have limitations on picking the right materials and processing steps to form a working junction due to, for example, lattice mismatch, doping, and band alignment. In this work, we then demonstrated a new approach to realize the charge carrier separation in solar cells with the bound surface charges on ferroelectric. The appearance of bound surface charges leads to an induced voltage V between the two surfaces of the ferroelectric. The induced voltage V is then applied on the semiconductor as an external electric field to enhance the charge separation in the semiconductor. Detailed theoretical calculations and experimental results verify the feasibility of the new concept, although the device performance is still poor at the moment. We are therefore confident that our new concept cell is promising because of its many advantages over traditional junction-based solar cells such as more options in choosing semiconductors for solar cells, more flexibility in device design, good potential in achieving high performance, and simple processing steps.