Wide bandgap materials show great promise as an alternative to the current state-of-the-art semiconductor technology based on Si because of its limitation in high-power and high-frequency applications. Among these wide bandgap semiconductors, diamond has exhibited great potential for use in high-power, high-temperature electronics due to its extraordinary properties, including high bandgap (5.47 eV), high thermal conductivity (2000 Wm–1) and high carrier mobility (3000 cm2V–1s1) [1]. However, significant challenges are associated with impurity doping of the constrained diamond lattice that remains a primary impediment to the development of diamond-based electronic devices [2]. An alternate method known as 'surface transfer doping' has recently been explored, which uses the negative electron affinity of hydrogen-terminated diamond (H:Diamond) surfaces to produce a two-dimensional hole gas beneath the surface [3]. However, extensive research is needed to fully understand the surface doping mechanism and its reliability in real-time devices and applications. As a first step towards accomplishing surface transfer doping in in-house grown H: Diamond, this study investigated the use of air absorbents and Molybdenum oxide (MoO3) as a surface electron absorber. Using contact angle and electrical conductivity measurements, the generation of hole gas beneath the surface of H:Diamond was confirmed. These preliminary results will be useful to the development of diamond-based high-power transistors as well as other electronic devices.
References:
1. Das, Dhruba et.al. "Diamond-The Ultimate Material for Exploring Physics of Spin-defects for Quantum Technologies and Diamontronics." Journal of Physics D: Applied Physics (2022).
2. Wort, Chris JH, and Richard S. Balmer. "Diamond as an electronic material." Materials today 11, no. 1-2 (2008)
3. K.G.Crawford et al, "Surface transfer doping of diamond: A review", Progress in Surface Science, 96 (1), 100613 (2021)