Excitation wavelength dependence of terahertz emission from InN and InAs

Abstract

The authors report on the excitation wavelength dependence of terahertz emission from n-InN and bulk p-InAs pumped with femtosecond pulses tunable from 800 to 1500 nm. The terahertz amplitude, normalized to pump and probe power, from both narrow band gap semiconductors remains relatively constant over the excitation wavelength range. In addition, terahertz radiation from In-and N-face InN samples with bulk carrier concentrations ranging from 10 17 to 10 19 cm −3is also investigated, showing a strong dependence of terahertz emission on bulk carrier concentration. The experimental results agree well with calculations based on drift-diffusion equations incorporating momentum conservation and relaxation.

PAMBE growth and in‐situ characterisation of clean (2 × 2) and (√3 × √3) R30° reconstructed InN(0001) thin films

“…Particularly, the possibility of producing high efficiency InN-based terahertz emitters facilitates a wide variety of applications [7,8]. Besides the bulk characteristics, an increasing interest in the surface properties, which have strong impact on the electrical properties of InN-based devices, can be noticed.…”

Nitride semiconductors as terahertz sources based on spontaneous and piezoelectric polarization

“…Figure 1 shows a comparison of the time-resolved THz signal from the c-plane InN/InGaN MQWs (red curves) compared to c-plane InN (black curves) at a pump wavelength ranging from 800 nm to 1700 nm. Similar to InAs, the main THz generation mechanism in c-plane InN at low pump intensities is the photo-Dember effect [13,14]. In the MQW structure, THz generation is due to the interplay of drift and diffusion.…”

Correlation between switching to n-type conductivity and structural defects in highly Mg-doped InN

“…, and it was attributed to In-vacancy and N-vacancy clusters-V In (V N ) 3 . 20 Such complex, however, is expected to exhibit a very high formation energy as predicted by first-principles calculations 23 and therefore more difficult to form.…”

“…Accurate control of p-type doping in InN is a critical issue on the way to material implementation in advanced electronic devices such as next generation solar cells, light emitting diodes, 1,2 and terahertz emitters. 3 So far, only Mg has been shown as a working acceptor for InN. 4 Due to peculiarities of energy band structure, intrinsic InN is extremely prone to n-type behavior.…”