An Expanded Cox and Strack Method for Precise Extraction of Specific Contact Resistance of Transition Metal Oxide/n-Silicon Heterojunction

Specific contact resistance $(\rho _{c})$ , commonly extracted by Cox and Strack method (CSM) and transfer length method (TLM), is one of the most important properties of carrier-selective contacts. However, in most cases, the hole-selective contacts (HSCs) deposited on n-type silicon (n-Si) substrate are Schottky heterojunction other than Ohmic contact, impeding the accurate extraction of $\rho _{c}$ by CSM and TLM. In this paper, an expanded CSM is proposed to precisely extract the $\rho _{c}$ of MoO _x /n-Si heterojunction, achieving a generally lower coefficient of variation. The current transport characteristic and the $\rho _{c}$ value of MoO _x /n-Si heterocontact are further verified by technology computer aided design (TCAD) simulation. The results demonstrate that the expanded CSM enables a more precise $\rho _{c}$ extraction, a better preparation technology compatibility, and a wider range of application, compared to TLM.