TY - JOUR

T1 - Angle-Selective Photodetection in Ge/Si Quantum Dot Photodiodes Enhanced by Microstructured Hole Arrays

AU - Yakimov, Andrew I.

AU - Kirienko, Victor V.

AU - Bloshkin, Aleksei A.

AU - Utkin, Dmitrii E.

AU - Dvurechenskii, Anatoly V.

N1 - This research was funded by Russian Science Foundation (grant 19-12-00070-Π).

PY - 2023/7

Y1 - 2023/7

N2 - We report on the near-infrared (NIR) photoresponse of a micropatterned Ge/Si quantum dot (QD) pin photodiode at different angles of radiation incidence. The photon-trapping hole array was etched through the n+-type top contact layer to reach the buried QDs. The normal-incidence responsivity was observed to be resonantly increased at wavelengths of 1.4, 1.7, and 1.9 (Formula presented.) m by factors of 40, 33, and 30, respectively, compared with the reference detector without holes. As the incident angle (Formula presented.) increases, the resonance peaks are disappeared and at (Formula presented.) a new resonance with a (Formula presented.) enhancement arises at a wavelength of 1.8 (Formula presented.) m. Simulation of the near-field intensity, Poynting vector distribution and wave polarization showed that at small (Formula presented.), the strong electric field is primarily localized under the air holes (1.4 (Formula presented.) m, TM mode) or between the holes (1.7 and 1.9 (Formula presented.) m, TE modes) inside the region occupied by QDs, resulting in the strong NIR photocurrent. At large (Formula presented.), the dominant resonance detected at 1.8 (Formula presented.) m is the result of coupling between the TE and TM modes and formation of a mixed near-field state.

AB - We report on the near-infrared (NIR) photoresponse of a micropatterned Ge/Si quantum dot (QD) pin photodiode at different angles of radiation incidence. The photon-trapping hole array was etched through the n+-type top contact layer to reach the buried QDs. The normal-incidence responsivity was observed to be resonantly increased at wavelengths of 1.4, 1.7, and 1.9 (Formula presented.) m by factors of 40, 33, and 30, respectively, compared with the reference detector without holes. As the incident angle (Formula presented.) increases, the resonance peaks are disappeared and at (Formula presented.) a new resonance with a (Formula presented.) enhancement arises at a wavelength of 1.8 (Formula presented.) m. Simulation of the near-field intensity, Poynting vector distribution and wave polarization showed that at small (Formula presented.), the strong electric field is primarily localized under the air holes (1.4 (Formula presented.) m, TM mode) or between the holes (1.7 and 1.9 (Formula presented.) m, TE modes) inside the region occupied by QDs, resulting in the strong NIR photocurrent. At large (Formula presented.), the dominant resonance detected at 1.8 (Formula presented.) m is the result of coupling between the TE and TM modes and formation of a mixed near-field state.

KW - near-infrared photodetection

KW - photon-trapping microstructures

KW - quantum dots

KW - telecom

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85166295394&origin=inward&txGid=0ad5e2da31433e910eacc19e5d98c58b

UR - https://www.mendeley.com/catalogue/bbfcf5f1-19ab-3f6b-83b5-2e3ddd61b4a9/

U2 - 10.3390/photonics10070764

DO - 10.3390/photonics10070764

M3 - Article

VL - 10

JO - Photonics

JF - Photonics

SN - 2304-6732

IS - 7

M1 - 764

ER -