Mukhopadhyay Partha, Schoenfeld Winston V
Appl Opt. 2019 May 1;58(13):D22-D27. doi: 10.1364/AO.58.000D22.
We report on tin gallium oxide ((SnGa)O) 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=10%. Incorporation of Sn into GaO 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.
我们报道了通过等离子体辅助分子束外延在c面蓝宝石衬底上生长的氧化锡镓((SnGa)O)日盲金属-半导体-金属(MSM)光电探测器，其锡含量最高可达X = 10%。研究发现，将Sn掺入GaO中会使外延层的光学带隙从含0% Sn时的5.0 eV(248 nm)转变为含10% Sn时的4.6 eV(270 nm)。还发现，改变Sn浓度能够对由外延层制成的MSM器件的峰值响应度和截止波长进行可控调谐，随着Sn浓度从0%增加到10%，峰值响应度范围从0.75 A/W到近16 A/W。高响应度归因于光电导增益，其随着Sn浓度的增加而增大，同时MSM探测器的时间响应会变慢。
