High-Performance, Vacuum-Free, and Self-Powered CsPbIBr2 Photodetectors Boosted by Ultra-Wide-Bandgap Ga2O3 Interlayer

In this letter, ultra-wide-bandgap Ga ₂ O ₃ as the interlayer is grown by mist chemical vapor deposition (mist-CVD) between perovskite and TiO ₂ electron transport layer in perovskite photodetectors (PDs). To get a stable working condition and low-cost fabrication, all-inorganic CsPbIBr ₂ is adopted and the expensive vacuum-deposited metal electrode is replaced by printing carbon paste. The vacuum-free, self-powered CsPbIBr ₂ PD with Ga ₂ O ₃ interlayer achieves an obviously improved performance, with a low dark current of 4.15 × 10 ^-9 A, high responsibility of 0.22 A/W, fast response time of 1.83μs, and high peak specific detectivity of 1.83×10 ¹² Jones. This work provides a strategy to develop high-performance self-powered PDs with the ultra-wide-bandgap Ga ₂ O ₃ interlayer and a reduced cost.