Defect Engineering of P-type Transparent Oxide Semiconductor


CALL: 2012

DOMAIN: MS - New Functional and Intelligent Materials and Surfaces


LAST NAME: Lenoble




KEYWORDS: Transparent Oxide Semiconductor, p-type functional oxide, crystalline point-defect, p-n junctions

START: 2013-09-01

END: 2016-12-31


Submitted Abstract

Transparent conductive films are found routinely in our daily life (low-emissivity windows based on glass coated with F-doped SnO2, front surface electrodes for solar cells and flat-panel displays, electrochromic mirrors, defrosting windows, static dissipation, electromagnetic shielding etc. [4]) and are mainly based on highly conductive (> 1000 S/cm) n-type oxide semiconductors. When reporting in 1997 a transparent semiconducting material (CuAlO2) with “reasonable” p-type conductivity, H. Kawazoe [1] and his co-workers opened a new era of “invisible electronics” [2] built on active devices such as diodes. Among p-type transparent semiconductors, Cu(I)CrO2:Mg delafossite oxides, deposited by RF-sputtering, showed the best reported conductivity (220 S/cm) [3] when compared to other p-type semiconducting oxides. Most of the reported devices still suffer from irreproducible p-type conductivity (typically 2 or 3 orders of magnitude lower than the published data by Nagarajan et al.[3]). Novel material strategies need to be anticipated to further improve the conductivity (>100 S/cm) and the transparency (>80% transmittance) of the p-type TOS. Tuning accordingly the Fermi-level of p-type TOS is also a foreseen request to optimize the overall band structure, from the active junction to the contact electrode, of the future transparent device. Other approaches to enhance the p-type conductivity and transparency of delafossite CuMO2 have yet to be investigated including i) the formation of Cu vacancies ii) the formation of O interstitials and iii) a combination of both. By smartly engineering the point-defect profile and concentration into the advanced TOS materials with ion implantation, a novel path to improve the actual performance trade-off (conductivity versus transparency) of p-type TOS is proposed. This research may be easily implemented for optimizing the device performances integrated on future smart glasses or intelligent foils developed in Luxembourg.[1] H. Kawazoe, et al., Nature 389 (1997), 939-942 [2] G. Thomas, Nature 389 (1997), 907-908, [3] R. Nagarajan, N. Duan, M.K. Jayaraj, J. Li, K.A. Vanaja, A. Yokochi, A. Draeseke, J. Tate, A.W. Sleight, International Journal of Inorganic Materials 3 (2001), 265-270[4] R. G. Gordon, MRS Bulletin, August 2000, 52-57

This site uses cookies. By continuing to use this site, you agree to the use of cookies for analytics purposes. Find out more in our Privacy Statement