THz generation from a nanocrystalline silicon-based photoconductive device

Abstract

Terahertz generation has been achieved from a photoconductive switch based on hydrogenated nanocrystalline silicon (nc-Si:H), gated by a femtosecond laser. The nc-Si:H samples were produced by a hot wire chemical vapour deposition process, a process with low production costs owing to its higher growth rate and manufacturing simplicity. Although promising ultrafast carrier dynamics of nc-Si have been previously demonstrated, this is the first report on THz generation from a nc-Si:H material.

Enhanced terahertz emission by coherent optical absorption in ultrathin semiconductor films on metals

“…This leads to the emission of stronger THz pulses. THz generation from nano-crystalline Si in a photo-conductive switch was reported in 2011 [14].…”

Generation and detection of Terahertz radiation from low temperature gallium arsenide photoconductive antennas using autocorrelation technique

“…Coherent detection techniques such as photoconductive sampling [ 1 ],electrooptic sampling [2] are restricted in characterizing the THz pulses, due to their limited band width detection [3] in gated photo conducting (PC) antennas and strong dispersion at optical phonon frequencies in crystals [4], respectively. To root out, inability of detecting THz using PC antenna and crystals, THz generation by interferometry(or autocorrelation) [5][6][7] is a suitable method which uses the incoherent detectors, namely bolometer, Golay cell and pyro electric detectors [8]. Aforementioned detectors are thermal sensors and are capable of detecting a broad spectral range of THz.Among the mentioned detectors, bolometer is highly sensitive with fast response to THz essentially need cryogenic cooling system which is more expensive.…”