| Title |
Spectral dependence of THz emission from InN and InGaN layers / |
| Authors |
Norkus, Ričardas ; Aleksiejūnas, Ramūnas ; Kadys, Arūnas ; Kolenda, Marek ; Tamulaitis, Gintautas ; Krotkus, Arūnas |
| DOI |
10.1038/s41598-019-43642-4 |
| Full Text |
|
| Is Part of |
Scientific reports.. London : Nature Publishing Group. 2019, vol. 9, art. no. 7077, p. 1-6.. ISSN 2045-2322. eISSN 2045-2322 |
| Keywords [eng] |
semiconductors ; THz ; InGaN |
| Abstract [eng] |
Spectral dependence of terahertz emission is a sensitive tool to analyze the structure of conduction band of semiconductors. In this work, we investigate the excitation spectra of THz pulses emitted from MOCVD-grown InN and InGaN epitaxial layers with indium content of 16%, 68%, and 80%. In InN and indium-rich InGaN layers we observe a gradual saturation of THz emission efficiency with increasing photon energy. This is in stark contrast to other III-V semiconductors where an abrupt drop of THz efficiency occurs at certain photon energy due to inter-valley electron scattering. From these results, we set a lower limit of the intervalley energy separation in the conduction band of InN as 2.4 eV. In terms of THz emission efficiency, the largest optical-to-THz energy conversion rate was obtained in 75 nm thick In0.16Ga0.84N layer, while lower THz emission efficiency was observed from InN and indium-rich InGaN layers due to the screening of built-in field by a high-density electron gas in these materials. |
| Published |
London : Nature Publishing Group |
| Type |
Journal article |
| Language |
English |
| Publication date |
2019 |
