P‐type Near‐Infrared Transparent Delafossite Thin Films with Ultrahigh Conductivity

Design and implementation of efficient p‐type transparent conducting (TC) oxides with excellent performance are the global material challenge. The strategy of “chemical modulation of the valence band” triggers the enthusiasm for p‐type TC delafossite CuMO2. However, the low conductivity of previous CuMO2 films obstructs the development of delafossite‐based electronics. Herein, a new p‐type 4d transition metal Rh‐based CuRhO2 film with large‐size is first designed and fabricated by a facile solution method. Room‐temperature conductivity as high as 735 S cm−1 is achieved by substituting 10%Mg in Rh sites. Additionally, the acceptor‐doped CuRhO2 films exhibit high near‐infrared transmittance of 85–60% with low room‐temperature sheet resistance of 4.28–0.18 kΩ sq−1. Furthermore, the electronic structure, electrical transport mechanism, and intra‐band excitation feature for the CuRhO2 film are unveiled. The theoretical and experimental results make a great advance in p‐type TC films and will pave a promising blueprint for future multifunctional opto‐electronic devices.