Rеvuе des Energies Renouvelables
Volume 18, Numéro 1, Pages 1-8
2015-03-31

Adequate Method To Study The Surface Passivation Effectiveness In Hem Multicristallin Silicon Wafers

Authors : Bouhafs D. . Khelifati N. . Boucheham A. . Palahouane B. .

Abstract

In this work we have examined the effectiveness of surface passivation on ascut multicrystalline silicon (mc-Si) wafers using different techniques. The study is based on minority carrier lifetime measurements with quasi steady state photo-conductance, ‘QSSPC’. Effective minority carrier lifetime (τeff) measured values of 12.4, 8.9, 4.9 and 3.1 μsec are obtained respectively with four silicon surface passivation techniques: 1- Shallow phosphorous diffusion emitter (n+p), 2- Iodine-Ethanol (I-E), 3-Hydrofluoric acid (HF) emersion and 4- SiNx layer deposition. These results suggest that the shallow n+p emitter gives the eff close to the bulk lifetime (τb) due to the better surface passivation quality. Simulations made with Hornbeck-Haynes model indicate that the τeff improvement can be correlated with the decrease of the surface recombination velocity (SRV) and the increment of bulk lifetime.

Keywords

Lifetime measurement, Multicrystalline silicon, Surface passivation, Minority carrier.