Open-circuit voltage decay: moving to a flexible method of characterisation
Decroissance de la tension en circuit-ouvert : vers une methode de characterisation polyvalente
Résumé
Open-Circuit Voltage Decay is a method to characterize minority carrier effective lifetime (τeff). It is non-destructive, simple and low-cost. It has been mainly used in silicon p-n junctions. τeff is a very important parameter to optimize device design but also to supervise process steps. Actually, it is not the only parameter we can obtain by OCVD. Due to the intrinsic space charge region (SCR) capacitance of a p-n junction, doping level of the lowest-doped region (Nl) and built-in potential (Vbi) are extractable. Moreover, it is also possible to obtain the shunt resistance (Rsh) value when it has a significant effect on the p-n junction behaviour. We first applied the well-established one-diode model in transient regime to simulate OCVD signal. In a second step, we used an optimization algorithm to fit the experimental curve of a silicon diode in order to extract τeff , Nl , Vbi and Rsh. These values were compared to those obtained from C-V and I-V. Results are promising and demonstrates for the first time, the flexibility of the OCVD method. It opens up the perspective for development of add-on features of the method and for measuring short lifetime.
Domaines
Physique [physics]
Origine : Fichiers produits par l'(les) auteur(s)
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