A method for forming low resistance contact to p-CdTe

This brief contains an investigation on the method for obtaining a stable low resistance ohmic contact to p-CdTe thin film. The contact was obtained by introducing a thin Cu_xO (0 < x ≤ 1) layer in between the metal and CdTe. The oxide layer mediated the contact by a charge polarization effect. The specific contact resistances between metal-CdTe were analyzed with and without a Cu_xO layer. It has been observed that contacts mediated by charge polarization effects offer comparably low resistance and better stability than the contacts obtained by the dopant-induced surface fields. The new type of contacts employ polarization of charges to enhance a tunneling transport mechanism. Experimental results on various metal contacts to p-CdTe are presented. The contacts have linear current-voltage (I-V) characteristics with a contact resistance of 2.2 × 10^-2 Ω-cm², as obtained from linear TLM measurements. To the best of our knowledge, this is the first time this type of contact has been reported.