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 (Eg) 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 Ilight/Idark 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.