Characteristics of InAlAs/InGaAs high-electron-mobility transistors under illumination with modulated light

A time- and frequency-domain characterization of a thin-film metamorphic HEMT under modulated backside illumination

“…Light induces more carriers into the channel, thus leading to an increase in conductance g gsx , that is, the photoconductive effect. The reason for the increase in g m arises from (i) a reduction in source resistance due to an increase in the concentration of the 2DEG, or (ii) a decrease in the effective channel thickness due an increase in the internal field of the 2DEG caused by the photogenerated holes [10]. It is not known which mechanism is dominant.…”

“…The response is difficult to observe, since the gain produced by the photoconductive effect is much smaller than the gain produced by the photovoltaic effect [10].…”

Fast High‐Responsivity Few‐Layer MoTe2 Photodetectors

“…This mechanism, associated with the photovoltaic effect, is called photogating and has been observed in many semiconductor photodetectors. [19,28,29] The explanation for photogating in a hole doped device is that photogenerated electrons are captured in trap states causing the potential barrier at the interface between MoTe 2 and the Cr/Au electrode to decrease. The electric field is reduced from the accumulated charge, allowing holes to travel through the circuit more freely increasing conduction.…”

InAlAs/InAs/InGaAs pseudomorphic high electron mobility transistors exhibiting ultra‐fast optical response

“…The minimum value of τ was 3.5x10 -11 s. The distance for a hole to transit across the channel equals L g (1.0 μm) and the drift velocity of holes was estimated to be 2.5x10 6 cm/s [4].…”

“…In our previous study on what effects optical irradiation had on InAlAs/InGaAs HEMT characteristics, we demonstrated that the kink effect in InAlAs/InGaAs HEMTs is caused by a shift in the threshold voltage (V TH ), which arises from the change in the Fermi level because of an accumulation of holes in the source region [3,4]. The carrier lifetime of accumulated holes is dominated by the recombination of holes with two-dimensional electron gas (2DEG) [5,6].…”