Back-contact structures for optoelectronic devices: Applications and perspectives

Interdigitated back contact (IBC) structures formed by integrating two functional materials of opposite polarity on the rear side of device have attracted a significant attention for optoelectronic device design. Currently, this type of IBC design has been widely developed with a variety of applications in the photovoltaic (PV) community and associated fields. In terms of PV devices, the IBC designs can eliminate the need for a front electrode, endowing a potential in high power conversion efficiency. Moreover, by opening the front surface on IBC structures provides a platform for further designs, which enables us to realize a series of derived applications. This review summarizes the recent progress in IBC based PV devices, including c-Si solar cells (SCs), perovskite SCs, and perovskite/c-Si tandem SCs. Furthermore, the focus herein is focused on the latest advances in the specific applications in the studies of photon recycling, and in-situ/in-operando measurements of photoelectric properties. Finally, a perspective into the remaining challenges and future opportunities to accelerate the practical applications of IBC devices is highlighted. [Display omitted] •A systematic review including physical mechanism and design principles is summarized.•A large number of applications for optoelectronic devices are covered, which is of great interest to not only the fundamental researchers but also to the photovoltaic industry.•The content presented in this review includes many of the latest reports and sheds new light on the device designs and characterization.