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

Yan Yang; Weiming Liu; Tiantian Huang; Mengxia Qiu; Rui Zhang; Wanli Yang; Junbo He; Xin Chen; Ning Dai

doi:10.1021/acsami.1c11692

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

ACS Appl Mater Interfaces. 2021 Sep 8;13(35):41802-41809. doi: 10.1021/acsami.1c11692. Epub 2021 Aug 26.

Authors

Yan Yang^{1

2}, Weiming Liu^{1

3}, Tiantian Huang¹, Mengxia Qiu¹, Rui Zhang¹, Wanli Yang¹, Junbo He^{1

3}, Xin Chen^{1

4

2}, Ning Dai^{1

4

2}

Affiliations

¹ National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
⁴ Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.

PMID: 34435500
DOI: 10.1021/acsami.1c11692

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 (E_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_light/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.

Keywords: MoS2 multilayers; amorphous gallium oxides; atomic layer deposition; flexible devices; solar blind photodetectors.