Analytical Estimation of Recombination Current of Sharp Asymmetric p-n Junction

Authors A.B. Galat, A.L. Donchenko

Kharkiv National University of Radio Electronics, 14, Nauky Ave., 61166 Kharkiv, Ukraine

Issue Volume 11, Year 2019, Number 5
Dates Received 24 May 2019; revised manuscript received 21 October 2019; published online 25 October 2019
Citation A.B. Galat, A.L. Donchenko, J. Nano- Electron. Phys. 11 No 5, 05005 (2019)
PACS Number(s) 73.40.Lq
Keywords Recombination through traps, Current of recombination, Coefficient of ideality, Differential coefficient of ideality, Photoelectric converter, Errors of calculation.

When simulating an asymmetric p-n junction, the high-alloyed region in the approximation of small currents does not affect the distribution of carriers in the low-alloyed region, in which the entire volume charge is concentrated. In this paper, an analytical estimate of the recombination current through traps in the space charge region and in the quasi-neutral region was made. To obtain an analytical representation, an approximation of the linearity of the potential distribution in the vicinity of the maximum recombination cross section is used. A method is proposed to analytically estimate the integral of the specific volume recombination rate over a region of the space charge that cannot be taken through elementary functions. The possibility of increasing the accuracy of the analytical estimate of the recombination current through traps in the space charge region was confirmed. The differential ideality coefficient is determined and its dynamics is analyzed depending on the voltage at the junction. Comparative analysis of the following recombination current estimates was made: the recombination current in the space charge region by elementary estimate, the diffusion current from the low-alloyed quasi-neutral region, the recombination current through traps in the quasi-neutral region, the current in the case of a linear approximation of the potential in the region of maximum recombination through the analytical integral, the real recombination current. An analysis of the error in the calculation of the recombination current from the doping level of the low-doped region and the applied voltage is presented. From the above data it can be seen that the error estimate for calculating the current through the analytical integral does not exceed 10 %, which is quite enough for its use in simulating the recombination current of most power semiconductor devices.

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