The formation process of the B- and O-related defect complex in crystalline Si, responsible for the performance degradation of solar cells made on B-doped Czochralski Si, was investigated in Czochralski–Si solar cells as a function of the applied voltage - in the dark - at 298 to 373K. It was shown that the defect formation was not only a consequence of illumination or the application of a forward bias voltage but also occurred under equilibrium conditions at elevated temperatures in the dark. It could be partly suppressed by applying a reverse voltage. The findings provided clear experimental evidence that a recombination-enhanced mechanism, related to the total recombination rate, was the driving force for formation of the metastable defect.

Recombination-Enhanced Formation of the Metastable Boron–Oxygen Complex in Crystalline Silicon. K.Bothe, R.Hezel, J.Schmidt: Applied Physics Letters, 2003, 83[6], 1125-7