Ultrahigh responsivity of optically active, semiconducting asymmetric nano-channel diodes

19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures

Akbas, Y.^1 ; Stern, A.^1 ; Zhang, L.Q.^2 ; Alimi, Y.^2 ; Song, A.M.^2 ; Iñiguez-De-La-Torre, I.^3 ; Mateos, J.^3 ; González, T.^3 ; Wicks, G.W.^1 ; Sobolewski, Roman^1

University of Rochester, Rochester

NY

14627-0231, United States^1

University of Manchester, Manchester

M13 9PL, United Kingdom^2

Universidad de Salamanca, Salamanca

E-37008, Spain^3

关键词: Continuous wave lights;    InGaAs/InAlAs quantum well;    Laser illumination;    Light illumination;    Optical characterization;    Orders of magnitude;    Single-photon level;    Transport currents;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/647/1/012013/pdf
DOI  :  10.1088/1742-6596/647/1/012013

来源: IOP

【 摘 要 】

We present our research on the fabrication and optical characterization of novel semiconducting asymmetric nano-channel diodes (ANCDs). We focus on optical properties of ANCDs and demonstrate that they can be operated as very sensitive, single-photon-level, visible-light photodetectors. Our test devices consisted of 1.2-μm-long, ∼200- to 300-nm-wide channels that were etched in an InGaAs/InAlAs quantum-well hetero structure with a twodimensional electron gas layer. The ANCD I-V curves were collected by measuring the transport current both in the dark and under 800-nm-wavelength, continuous-wave-light laser illumination. In all of our devices, the impact of the light illumination was very clear, and there was a substantial photocurrent, even for incident optical power as low as 1 nW. The magnitude of the optical responsivity in ANCDs with the conducting nano-channel increased linearly with a decrease in optical power over many orders of magnitude, reaching a value of almost 10,000 A/W at 1-nW excitation.