A Study of a‐Sic/C‐Si(n) Isotype Heterojunctions

Abstract

In the present work a study of the electrical properties of heterojunctions between rf sputtered amorphous silicon carbide (a-SiC) thin films and n-type crystalline silicon (c-Si) substrates is reported. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics, as well as the temperature dependence of the current of a-SiC/c-Si(n) heterojunctions were measured. The I-V characteristics of a-SiC/ c-Si(n) heterojunctions exhibit poor rectification properties, with a high reverse current, at higher temperatures (T > 250K), whereas good rectification properties are obtained at lower temperatures (T < 250K). It was found that the a-SiC/c-Si(n) heterojunctions are isotype, suggesting that-the conductivity of a-SiC is n-type. The temperature dependence of the current (from 185K to 320K) showed that the majority carriers of c-Si(n) (i.e. electrons) are transported from c-Si(n) to a-SiC mainly by the thermionic emission mechanism, or by the drift-diffusion mechanism. From C-V measurements of a-SiC/c-Si(n) heterojunctions the electron affinity of a-SiC was found to be X 4.20 --. -0.04 eV. Finally, the a-SiC/ c-Si(n) isotype heterojunctions are expected to be interesting devices as infrared detectors.

The a‐SiC/c‐Si(n) Isotype Heterojunction as a High Sensitivity Temperature Sensor

“…l(b)). The above energy band diagram was calculated, in our previous study [13], using Anderson's model [14]. The conductivity of a-SiC was considered to be n-type, as it was found in our previous works [12,13].…”

“…MetalAmorphous Silicon FETs [4,5], thin film Transistors [6], Optothyristors [7], and Heterojunction Phototransistors [8] there is no published work in the area of temperature sensors using amorphous semiconductors. Taking, also, into account that localized gap states have a crucial effect on the electrical properties of amorphous semiconductor materials [9,10] and devices [11] [12,13] The reverse current-voltage (1R-V) and voltage-temperature measurements (V-T) of a-SiC/c-Si(n) isotype heterojunctions were carried out within a light-tight cryostat evacuated down to 10 -3 Torr, in the temperature range from 230 K up to 320 K, using a picoameter and a current source controlled by a P.C. 3.…”

Fabrication and Characterization of Carbon Nanofiber-Based Vertically Integrated Schottky Barrier Junction Diodes

“…Given φ b = 0.3 eV as determined above and neglecting barrier contributions of interface states, an electron affinity, χ, of 4.1 eV for the semiconducting material between the nanofiber and the Si is obtained using the relation φ b = φ m − χ. This value agrees well with published values of χ for SiC …”