Title :
Gate controlled Ge/SiGe QD/QW photo-MESFETs for high photo-response at 1.31-1.55 μm
Author :
Elfving, A. ; Hansson, G.V. ; Ni, W.X.
Author_Institution :
Dept. of Phys., Linkoping Univ., Sweden
fDate :
29 Sept.-1 Oct. 2004
Abstract :
This paper demonstrates the fabrication of near infrared MESFET photodetectors. This study shows that photon absorption occurs in Ge quantum dots while the lateral transport of photo-carriers is facilitated by high mobility 2D SiGe quantum wells next to the dot layers. High photo-response at normal incidence are measured, with the highest responsivity of 140 mA/W (1.31 μm) and >35 mA/W (1.55 μm) at room temperature. The measured integrated photo-responsivity for the photon beam with energies below the Si bandgap is >200 mA/W at VDS = -2.5 V and VG = 2 V. The time-resolved photoconductivity measurements and switch properties of these MESFET photodetectors are also studied with switching frequency of 3 MHz, which is the upper limit of the instrument bandwidth.
Keywords :
Ge-Si alloys; Schottky gate field effect transistors; electro-optical switches; germanium; photoconductivity; photodetectors; quantum well devices; semiconductor quantum dots; semiconductor quantum wells; -2.5 V; 1.31 to 1.55 mum; 2 V; 20 degC; 2D SiGe quantum wells; 3 MHz; Ge-SiGe; Ge/SiGe photoMESFET; MESFET photodetectors; QD/QW photoMESFET; Si bandgap; gate controlled photoMESFET; high mobility quantum wells; high photoresponse; integrated photoresponsivity; lateral photocarrier transport; near infrared photodetectors; photodetector fabrication; photon absorption; photon beam; quantum dots; room temperature; switch properties; time-resolved photoconductivity measurements; Energy measurement; Fabrication; Frequency measurement; Germanium silicon alloys; MESFETs; Photodetectors; Photonic band gap; Quantum dots; Silicon germanium; Switches;
Conference_Titel :
Group IV Photonics, 2004. First IEEE International Conference on
Print_ISBN :
0-7803-8474-1
DOI :
10.1109/GROUP4.2004.1416649
