Terahertz radiation from InAs induced by carrier diffusion and drift

Excitation wavelength dependence of terahertz emission from InN and InAs

“…There is no discernable difference between the In-and N-face InN samples, as expected for the improved crystalline quality and concomitant low background electron density and high mobility for both polarities. 9,16 Liu et al 13 have shown a similar dependence on carrier concentration for the terahertz radiation from InAs.…”

“…Additionally, at lower carrier densities, the optical rectification contribution is no longer the main terahertz generation mechanism in ͑111͒ InAs, but becomes comparable to effects due to the difference of the electron and hole diffusion coefficients ͑photo-Dember effect͒. 13 The possibility of terahertz emission from InN has been demonstrated by Ascazubi et al, 14 who attributed the terahertz generation mechanism to transient photocurrents but did not specify the exact mechanism. Similar to InAs, InN has a surface accumulation layer, which has a width that is more than an order of magnitude shorter than the optical absorption length.…”

Oscillations of electron–hole plasma in terahertz emitters

“…The dominant mechanism of THz emission from the (100) oriented InAs surface is the transient photocurrent induced by the photo-Dember effect [26,27]. The surface Fermi level in InAs is pinned at 0.2 eV above the conduction band edge [28].…”

Генерация терагерцового излучения при облучении фемтосекундными лазерными импульсами In-=SUB=-0.38-=/SUB=-Ga-=SUB=-0.62-=/SUB=-As, выращенного на подложке GaAs с метаморфным буферным слоем

“…В результате того, что подвижность электронов, как правило, выше подвижности дырок, в полупроводнике при поглощении оптического излуче-ния возникает пространственное разделение электронно-дырочных пар и, как следствие импульс тока, кото-рый генерирует ТГц излучение. Фотоэффект Дембера сильнее проявляется в полупроводниках с узкой за-прещенной зоной, например InAs или InN [17][18][19], а эффект ускорения электрон-дырочных пар встроенным электрическим полем -в полупроводниках с широкой запрещенной зоной, например GaAs..…”