A study on the voltage-dependent response of a GaInNAs-based pin photodetector with a quasi-cavity

Abstract

We present a characterisation of a GaInNAs/GaNAs quantum well-based photodetector with a bottom distributed Bragg reflector (quasi-cavity). The detector is designed to be used at the 1.3 μm optical fibre communication window. The quantum efficiency of the photodetector is measured as 24% at 1286 nm under −2 V applied reverse bias. As the reverse bias voltage is increased, a carrier multiplication-related increase and oscillations are observed in the voltagedependent responsivity curve. The observed carrier multiplication is explained by the high electrical field-induced impact ionisation mechanism in the pin junction region, while the observed voltage-dependent oscillations are explained by the Franz-Keldysh effect (FKE). At the wavelength of 1286 nm, which is close to the absorption wavelength of the active region of the photodetector, FKE-related oscillations (FKOs), start at very low reverse bias values and the responsivity of the photodetector is dominated by FKOs. On the other hand, FKOs quench at higher wavelengths and an impact ionisation-related increase at the voltage-dependent responsivity curve dominates. At λ=1310 nm, only impact ionisation mechanisms have an effect over the R (V) curve. The multiplication factor for 1310 nm is calculated as M=12 at room temperature. The applied electric field and excitation wavelength dependence of the absorption coefficient is calculated and a good match with the experimental results at the applied voltages is achieved.

Theoretical model of giant oscillations of the photocurrent in GaAs/AlAs p-i-n diodes

“…Similar quantum-size effects were also observed in the photocurrent of optically excited p-i-n GaAs/AlAs or InGaN/GaN superlattices [9,10]. Also, in a GaInNAs-based p-i-n photodetector were found voltage-dependent oscillations of the photoresponsivity are explained by the Franz-Keldysh effect (FKE) [11].…”

“…The amplitudes of both the oscillating and non-oscillating parts of the photocurrent depended linearly on the radiation power. These photocurrent oscillations were observed at a photon energy greater than the band gap of GaAs and did not depend on the light wavelength in the range from 830 to 360nm, which distinguished them from the oscillations due to the FKE [11,16] that has specific interplay between electric field strength and wavelength of the light. It was found in [12,15] that the frequency of the photocurrent oscillations in all the studied structures at a relatively low irradiation power did not depend on the design of the barrier region (one or two barrier structures, the presence or absence of InAs QDs in the barrier region), but depended only on the width undoped region between the barrier and the p + contact.…”

A novel NiO-based p-i-n ultraviolet photodiode

“…It may cause a red shift of the absorption edge, giving rise to the presence of an absorption tail below the bandgap and an oscillatory behaviour in the frequency of the optical properties of the semiconductor is revealed above the energy of the bandgap (inserted in Figure 5) [53]. It is well-known phenomena in the literature on thinfilm semiconductors and high-current photodetectors [51]. In other respects, the tail below the bandgap and nearly flat high responsivity above the bandgap compared to the NiO-based metalsemiconductor-metal photodetectors which show an interminable reduction of responsivity at the higher energy can also be attributed to the incorporation of the Cu and Mg atoms to the top and bottom NiO layers, respectively.…”

“…Franz-Keldysh effect is a physical phenomenon associated with the influence of a high electric field on near-band-edge absorption [51,52]. It may cause a red shift of the absorption edge, giving rise to the presence of an absorption tail below the bandgap and an oscillatory behaviour in the frequency of the optical properties of the semiconductor is revealed above the energy of the bandgap (inserted in Figure 5) [53].…”

SWCNT-Si photodetector with voltage-dependent active surface

“…Photodetectors are our society's most used technological devices, with applications in day-life, medical, military, and research fields [1][2][3][4]. They can be realized using different materials or structures [5][6][7][8][9] but the oldest and best-understood photonic devices, with commercial products that can operate in the range from 300 to 900 nm, are the silicon photodetectors [10]. Despite their advanced technology, different intrinsic problems, such for example, the low absorption in the ultraviolet (UV) and infrared (IR) regions, still limit their possible applications.…”