Open AccessTin gallium oxide solar-blind photodetectors on sapphire grown by molecular beam epitaxy
Author(s) -
Partha Mukhopadhyay,
Winston V. Schoenfeld
Publication year - 2019
Publication title -
applied optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.668
H-Index - 197
eISSN - 2155-3165
pISSN - 1559-128X
DOI - 10.1364/ao.58.000d22
Subject(s) - responsivity , molecular beam epitaxy , materials science , optoelectronics , sapphire , gallium , photoconductivity , photodetector , tin , tin oxide , optics , band gap , photocurrent , epitaxy , doping , laser , nanotechnology , layer (electronics) , physics , metallurgy
We report on tin gallium oxide ((Sn x Ga 1-x ) 2 O 3 ) solar-blind metal-semiconductor-metal (MSM) photodetectors grown by plasma-assisted molecular beam epitaxy on c-plane sapphire substrates with varying tin content up to X Sn =10%. Incorporation of Sn into Ga 2 O 3 was found to shift the optical bandgap of the epilayers from 5.0 eV (248 nm) for 0% Sn to 4.6 eV (270 nm) for 10% Sn content. Varying of the Sn concentration was also found to enable controlled tuning of the peak responsivity and cutoff wavelengths of MSM devices fabricated from the epilayers, with peak responsivity ranging from 0.75 A/W to nearly 16 A/W as the Sn concentration was increased from 0% to 10%. The high responsivity is attributed to photoconductive gain that increases for higher Sn concentrations and is accompanied by a slowing of the temporal response of the MSM detectors.