A group of scientists from Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences (CAS) developed novel p-type near-infrared (NIR) Transparent Conducting (TC) CuRhO2 thin films with ultrahigh conductivity, unveiling a new material of TC.
"They have extraordinary characteristics," explained WEI Renhuai, a physicist who led the team, "the NIR optical transmittance of this film can reach as high as 85~60% while maintaining the room-temperature sheet resistance at a low level."
The p-type TC has attracted a lot of attention in recent years. Although N-type TC is common in current market, the incorporation of p-type TC and n-type TC can realize invisible active circuit heterostructures.
Compared with traditional delafossite-based P-type TC, the room-temperature conductivity of this novel TC is much higher. It reached 735 S/cm by substituting 10%Mg in Rh sites when the traditional TC is just 300 S/cm.
Aside from ultrahigh conductivity, the films also exhibited high near-infrared transmittance of 85~60% with a low room-temperature sheet resistance of 4.28~0.18 kΩ/sq.
In the experiment, based on the first-principles calculations, scientists found that CuRhO2 showed p-type conducting characteristics and processed a narrow indirect bandgap of 2.31 eV. Meanwhile, the optical absorption in the NIR and visible range is much low. The larger Rh3+ ionic radius makes the CuRhO2 accept hole-type carriers with high concentration.
The great advance in p-type NIR TC CuRhO2 thin films, based on both theoretical calculations and experimental results, can significantly improve the development of future multifunctional invisible optoelectronic devices.
Fig. 1 Photo of ap-type NIR TCCuRhO2 thin film with 2 inches size.（Image by WEI Renhuai）
Fig. 2 Calculated electronic band structure for the CuRhO2 (left).Optical transmittance and room-temperature sheet resistance for 10%Mg-doped CuRhO2 thin films (right).（Image by WEI Renhuai）