Study of D. C. Characteristics of Si, Ge and GaAs p-i-n Avalanche Diodes by a New Non-iterative Method

Abstract

A detailed study of the d. c. characteristics of Si, Ge and GaAs p-i-n avalanche diodes is presented by using a non-iterative method which does not require the usual iterative process. The method involves numerical solution of an equation which is derived from the Poisson and continuity equations. The computation is started from the minimum field point in the space charge region using realistic field veriation of ionization rate of charge carriers. It is observed that the effect of space charge on the d. c. electric field profile increases with increase of d. c. current density and decreases with the decrease of depletion layer width. The location of the field minimum is at the centre of space-charge layer for GaAs, but is shifted from the centre in case of Si and Ge. It is also seen that the V-J characteristics exhibit space-charge- induced negative resistance at high current densities which becomes more pronounced with the increase of depletion layer width.

Indexing Terms:

• Avalanche Diodes
• P-I-N Diodes
• Device Characteristics
• Negative Resistance

Additional information

Notes on contributors

R. Ghosh

GHOSH, RANJAN: Bora in November, 1947, obtained the degrees of BSc with Honours in Physics, BTech and MTech in Radio Physics and Electronics from Calcutta University in 1967, 1969 and 1970 respectively. After undergoing a one-year practical training at Overseas Communication Services, Calcutta, he joined research from March 1972 at the Centre of Advanced Study (CAS) Radio Physics and Electronics, University of Calcutta. His areas of research are the IMPATT devices, related charge carrier properties and associated microwave circuits. Since January, 1978 he is working as a Research Assodate in a UGC sponsored Research Project on ‘IMPATT Devices and Circuits’ which is executed at CAS in collaboration with CEERI, Pilani.

B. B. Pal

PAL, B B (Dr): Born in Shylhet (now in Bangladesh), obtained BSc (Hons.) degree in Physics from the Presidency College, University of Calcutta in 1965 and BTech and MTech degrees in Radio Physics and Electronics from the Centre of Advanced Study in Radio Physics and Electronics, University College of Technology, C.U. in the year 1967 and 1968 respectively. In 1969. joined the Centre of Advanced Study in Radio Physics & Electronics as a Research Fellow and worked on the high-frequency properties of avalanche transit-time devices. In 1971, became a lecturer in the same department, and is still working there. In 1975, obtained PhD degree from the University of Calcutta on the studies on avalanche transit-time devices. At present, working as a co- investigator in a UGC sponsored research project on IMPATT devices and circuits in collaboration with CEERI, Pilani. Has published a number of original research papers. His subjects of interest are semiconductor physics and devices, microwave solid-state devices, superconductors etc.