DETERMINATION OF THE DlFFUSlON LENGTH AND SURFACE RECOMBINATION VELOCITY: TWO SIMPLE METHODS

J.C. DURÁN; G.L. VENIER; M.J.L. TAMASI; C.G. BOLZI; J. PLA; E.M. GODFRIN

Anaheim, USA

Conferencia; 26th IEEE Photovoltaic Specialists Conference; 1997

The present paper analyzes two new methods for the estimation of the diffusion length (Ld) and surface recombination velocity (S) through simple and inexpensive equipment. The first one is based on the behavior of the short circuit current (Jsc) under rear illumination, as a function of the cell width (d). In a general case, this model allows to determine Ld and the effective rear S by a numerical fitting. The second method uses crystalline silicon cells with localized diffusions. A geometry with linear diffusions is considered and the dependence of Jsc with the distance between those diffusions is analyzed by means of a one dimensional model. The second method is applied ton+pp+ solar cells elaborated in the Argentine Atomic Energy Commission (CNEA).