Do TLM really characterize the contact resistivity of Transition Metal Oxides based Carrier Selective Contacts?
Shanmugam Kailasam, Ramachandran Ammapet Vijayan, Dakshinamoorthy Amirthaganesan, Srivatsan Srinath, Varun Viswanathan, Sangaravadivel Masilamani, Muthubalan Varadharajaperumal
SASTRA Deemed University, Thanjavur, India

We have simulated the transfer-length-method (TLM) to extract the contact resistivity of Molybdenum Oxide (MoOx) over n-type crystalline silicon (c-Si(n)) based on two different test structures. Simulation predicts that the commonly used, fully coated MoOx­ based test structure could lead to erroneous contact resistivity under certain conditions like defect limited charge transport.  We found that the error is due to the charge carrier flow through the film instead of inverted c-Si(n) surface. This could explain the independent experimental observation of decreased contact resistivity and fill-factor for thicker MoOx films. Second test structure which is based on partially coated MoOx film captures the contact resistivity correctly however it requires further investigation in the validation of the technique. This work could lead to better characterization of contact resistivity of TMO based carrier selective contacts and further progress in this arena.

Area: Sub-Area 4.4: Passivated Contacts, Carrier Selective Contacts and Hetero-Junction Structures