Photogalvanic effects in non-centrosymmetric halide perovskites

Photogalvanic effects are characterized by the presence of light-polarization-dependent non-zero short circuit photocurrent and non-zero open circuit voltage in junction-free bulk non-centrosymmetric semiconductors and metals and have been attributed to the non-trivial Berry parameters of matter. Non-centrosymmetric ferroelectric and piezoelectric halide perovskites demonstrate a coexistence of excellent semiconducting properties, switchable or tunable Berry parameters and spin–momentum locking, and strong spin–orbit coupling, making them an ideal model system to explore the photogalvanic effects, and its use in characterizing topological properties, and to develop novel devices. In this Perspective, we describe various mechanisms to break inversion symmetry in halide perovskites and present the theory and mechanisms of the linear and circular photogalvanic effect in non-centrosymmetric halide perovskites. We discuss the roles of symmetry, strain, chemistry, interface and electric polarization on the linear and circular photogalvanic effect in non-centrosymmetric halide perovskites. We present the key opportunities and challenges of designing and harnessing photogalvanic effects in non-centrosymmetric halide perovskites for unconventional devices for spin computing, sensing and solar energy applications. Non-centrosymmetric ferroelectric and piezoelectric halide perovskites are an ideal model system to explore the photogalvanic effects. This Perspective discusses the opportunities and challenges of designing and harnessing photogalvanic effects in these materials towards unconventional devices for spin computing, sensing and solar energy applications.