18 - Perovskite solar cells: A review of architecture, processing methods, and future prospects

Abstract

Perovskite solar cells (PSCs) have attracted many researchers due to their excellent power conversion efficiency (PCE) of 25.2%, and can be a substitution for silicon solar cells as future technology. The efficiency of PSCs has been enhanced from 3.8% to 25% and has evolved to be better technology than copper indium gallium selenide or cadmium telluride solar cells. The properties of perovskite materials such as high ion mobility, long carrier charge lifetime, and long carrier charge diffusion length enable the materials to be utilized as a light-absorbing layer in solar cells. Perovskite solar cells have surprising intrinsic properties like excellent charge transport, dielectric constants, and less exciton binding energy with high device performance. The power conversion efficiency (PCE) of perovskite solar cells depends upon the specific functions of each layer composition and architecture. The device architecture of PSCs can influence different parameters like open circuit voltage, fill factor, short circuit current, and PCE of the device. The energy band gap, light absorption of specific wavelength, performance, and stability can be varied/changed by regulating the positons of different sites (A, B, or X site) in perovskite crystal structure. The improvement of different functions of layer structure influences PSC performance. The synthesis methods of perovskite also influence cell performance. Enhancement of PSC performance can be achieved by improving different synthesis methods by adopting compositional or defect or crystal growth engineering. The role of electron and hole transport layer is also important for movement of charge carriers toward respective electrodes. Therefore, selection of electron and hole transport material influence the performance of solar cell. The study of physical parameters like charge transport, ion migration, charge recombination, polarization, and defects in crystal are important to understand the operational mechanism of perovskite layer and transport layers. The main issues of PSCs are their stability and toxicity. The stability of perovskite crystal and transport layer under different environmental conditions is also important for performance of PSC and its commercialization. This chapter contains a discussion on the progress of perovskites as a light absorption material for third-generation solar cells, material modification, fabrication methods, device architecture, and stability of PSCs. The chapter will consider basic physics like exciton formation, point defects, ion migration, ferroelectric properties, charge transport, charge recombination, and other physical properties in PSCs for enhancing device performance.