Research Information System
Solid-State Electronics, vol.45, no.9, pp.1607-1611, 2001 (SCI-Expanded)
Unoxidized and oxidized porous silicon (PS) based metal/PS/c-Si photodetector structures have been prepared by anodization of 10 and 20000 Ωcm p-type silicon (c-Si) substrates. A quantum efficiency up to 0.7-0.8 in the wavelength range 0.4-0.7 μm, a detectivity up to 6 × 1011 cm Hz1/2/W and a response time less than 2 ns were obtained. It is shown that the noise characteristics of the best device structures are determined by a generation current. We found that in oxidized device structures and structures made from highly resistive substrates a highly conductive inversion (n-type) layer is formed in the c-Si substrate adjacent to the PS/c-Si heterojunction. The presence of this inversion layer leads to an increase of the active device area, capacitance, noise current and response time. © 2001 Elsevier Science Ltd. All rights reserved.