High-performance IGZO/Ga2O3 dual-active-layer thin film transistor for deep UV detection

Owing to the intrinsically wide bandgap and high uniformity, amorphous Ga2O3 (a-Ga2O3) has been illustrating a great industrial potential for large-area deep ultraviolet (UV) photosensor arrays. However, a seemingly irreconcilable contradiction between high responsivity and long persistent photoconductivity has hampered the growing pace of such devices. In this work, three-terminal InGaZnO (IGZO)/a-Ga2O3 dual-active-layer (DAL) transistors were developed to realize the ability of a-Ga2O3 as the active layer both in switching and sensing. Benefitting from the introduction of ultrathin IGZO electron reservoir and defect control of a-Ga2O3, the DAL device demonstrates more stable and superior gate-control capability with promising performance including high on/off ratio and field-effect mobility of ~ 10(8) and 8.3 cm(2)/V center dot s, respectively, as well as a small sub-threshold swing (SS) of 0.36 V/dec. Under 254 nm UV illumination, the DAL device manifests a light-to-dark ratio of ~ 10(8), a responsivity of 4.8 x 10(3) A W-1, a detectivity of 8 x 10(15) Jones, and a UV/visible rejection ratio (R-254/R-400) of 64. The simultaneous achievement of deep UV photo-detection and transistor's switching performance in a-Ga(2)O(3 )material offers excellent potential for the construction of large-area active-matrix UV photosensor arrays with the simple and low-cost fabrication process. Published under an exclusive license by AIP Publishing.

Automated summary

This study developed three-terminal InGaZnO (IGZO)/a-Ga2O3 dual-active-layer (DAL) transistors, successfully realizing the ability of a-Ga2O3 as the active layer in both switching and sensing. By introducing an ultrathin IGZO electron reservoir and controlling the defects of a-Ga2O3, the DAL device demonstrated stable and superior gate-control capability with high on/off ratio, field-effect mobility, and low sub-threshold swing.