Investigation of low temperature amorphous (InxGa1−x)2O3 films modulated by indium content for optimization in solar-blind photodetector.

[Display omitted] • Amorphous (In x Ga 1- x) 2 O 3 films have been fabricated at RT using PLD and alloy targets.. • The effect of indium content on the characteristics of (In x Ga 1- x) 2 O 3 films and the performance of MSM solar-blind PDs has been explored in detail • The excessive indium atoms incorporated into the film leads to the formation of In-rich nano-clusters, which may be attributed to the segregation phenomenon because of the solid solubility limitation for indium in Ga 2 O 3. • The moderate indium content of (In x Ga 1- x) 2 O 3 can enhance the PDs performance. In this study, bandgap engineering of amorphous (In x Ga 1- x) 2 O 3 alloy films fabricated at room temperature using pulsed laser deposition and alloy targets with different indium contents from 0 % to 50 % have been investigated. The effect of indium content on the characteristics of (In x Ga 1- x) 2 O 3 films and the performance of metal–semiconductor-metal solar-blind photodetectors have been explored in detail. The moderate number of indium atoms introduced into Ga 2 O 3 can obtain a flat surface morphology and adjusted bandgap to enhance the performance of solar-blind photodetector. When the excessive indium atoms were incorporated into the film, the obviously In enriched (In x Ga 1- x) 2 O 3 alloy nano-clusters are observed on the film surface despite of the low growth temperature. It can be attributed to the segregation phenomenon because of the solid solubility limitation for indium in Ga 2 O 3. Both of dark current and photocurrent of (In x Ga 1- x) 2 O 3 photodetector increase with the incremental indium content mainly attributed to enhanced oxygen deficiency. As a result, the solar-blind photodetector can achieve an optimal performance using a balanced indium content of 20 % with an extremely low dark current of 4.4 × 10-12 A, a responsivity of 10.8 mA/W, a substantial on/off current ratio of 1.5 × 104 and a short rise/decay time of 0.33 s/0.54 s. [ABSTRACT FROM AUTHOR]