Low Deposition Temperature Amorphous ALD-Ga₂O₃ Thin Films and Decoration with MoS₂ Multilayers toward Flexible Solar-Blind Photodetectors

Abstract

Flexible sensors and photodetectors are among the robust and powerful strategies for advanced and smart devices. Meanwhile, wide band-gap metal oxides are competitive candidates for fabricating flexible solar-blind photodetectors (SBPDs) but still challenging in both fundamental and practical fields. Here, we demonstrate the amorphous ALD-Ga₂O₃ (am-ALD-Ga₂O₃) thin films realized at a moderate temperature toward flexible SBPDs. The bandgap (<i>E</i>_g) of 4.88-5.04 eV depends on and changes with the thickness of am-ALD-Ga₂O₃ thin films during atomic layer deposition (ALD) processes. The SBPDs are fabricated with the as-grown am-ALD-Ga₂O₃ thin films on desired substrates and exhibit an <i>I</i>_light<i>/I</i>_dark ratio of up to ∼4.5 × 10⁴ and dark current down to ∼10^-13 A. Subsequently, decorating the ALD-Ga₂O₃ channels with MoS₂ multilayers helps improve the photocurrent of SBPDs that worked in the deep ultraviolet region. We expect that our work will offer more opportunities to understand and exploit am-ALD-Ga₂O₃ thin films toward advanced flexible SBPDs and functional sensors.