From Materials to Device Engineering: Unravelling the Path to High Performance β-Ga2O3 based p-n Heterostructure Photodetectors

Abstract

The wide bandgap oxide semiconductor β-Ga₂O₃ with intrinsic solar-blind spectral selectivity and ability to operate in extreme harsh conditions makes it a go-to material for the design of future low-powered miniaturized photodetectors. The review comprehensively discusses the integration of β-Ga₂O₃ with different p-type class of materials (oxides, nitrides, organics, silicon-based, ferroelectric, two-dimensional semiconductors, perovskites and others) to realize p-n heterojunction; that offers built-in electric field which helps in light induced charge separation and promote charge collection efficiency. The review categorically discusses the challenges and critical role played by crystallinity, lattice mismatch, and band alignments for β-Ga₂O₃ based different p-n heterostructures. The review outlines different interface and nanostructure engineering techniques used to mitigate lattice mismatch effects and tailor the band-alignments at the interface of β-Ga₂O₃/p-layers to yield optimum photodetection. Then, application of myriad surface, dopant, contact, and heterojunction engineering techniques towards β-Ga₂O₃ based different p-n heterostructures for efficient light induced charge carrier generation, separation, transport, extraction and collection is discussed. The review outlines and compares for the first time, the current state-of-art diverse class of β-Ga₂O₃ based p-n heterostructure photodetectors in terms of their responsivity, detectivity and spectral selectivity; and advocates for future synergistical engineering approaches to unravel their true potential.