Study of optical sensors of the form A l/a-SiC:H/c-Si(n) with high sensitivity

Abstract

In the present work optical sensors of the form Al/a-SiC:H/c-Si(n), for different thickness of a-SiC:H thin films are studied. More specifically, a-SiC:H thin films were deposited by rf sputtering technique on c-Si(n) substrates for different thickness of the amorphous semiconductor and, subsequently, the samples were annealed in the temperature range from 300 o C up to 675 o C. Experimental measurements of the optical response of these sensors showed that for thicknesses of a-SiC:H greater than a critical value, which depends on annealing temperature, a mechanism of losses is appeared in the region of wavelengths from 525nm up to 625nm. This behaviour is attributed to the recombination of photo-generated electrons-hole pairs in the neutral region of a-SiC:H, when this exceeds the diffusion length of minority carries, L p . Also, the value of the reverse bias voltage appears to influence considerably the optical response of these sensors when d > L p in the case where the a-SiC: H thin films were annealed at 600 o C.

Ac Impedance Spectroscopy Of Al/A-Sic/C–Si(P)/Al Heterostructure under Illumination

“…3 is not the result of parasitic inductance. Similar explanation can be found in [18]. It is evident that the simple equivalent circuit with one parallel RC combination must be modified and the contribution of the interfacial states has to be taken into account.…”

“…Controllability of the band gap allows a wide range of applications especially in microelectronics, including thin dielectric layers and semiconductor applications. Optoelectronic applications as another important area include the use of a-SiC photodiodes in optical communications [17], optical/image sensors [18] and LED's applications [19]. Another field of applications a-SiC has found in micro electromechanical systems [20].…”

Study of the Electrical Behavior of Metal/α-SiC:H/poly-Si(N) Structure Using Simulation

“…The a-SiC:H * corresponding author; e-mail: ppapado@teikav.edu.gr thin lms are amorphous, exhibiting: (i) an optical energy band gap of E g = 3.2 eV, and (ii) an activation energy of dark conductivity E a = 0.85 eV. It should be noted that the a-SiC:H/c-Si(n) heterojunction is assumed to be isotype, since the sputtered a-SiC:H has been found to present an n-type behavior [5]. Its electrical behavior was investigated by utilizing the 2-D ATLAS advanced numerical simulator by simulating the I − V (currentvoltage) characteristics.…”

Study of Al/a-SiC/c-Si(p)/Al structure prepared by PECVD

“…This alloy (in thin film form) shows to be promising as both, etch stop [1,2] and hard mask layer [3] to assist nanoelectronic patterning, and as low dielectric constant (known as low-k) interfacial dielectric material [4], diffusion barrier [S-7], and pore sealants [8]. Optoelectronic applications as another important area include the use of a-SiC photodiodes in optical communications [9], optical/image sensors [10] and LED's applications [11].…”