Transparent Conducting Oxides (TCOs)

Transparent conducting oxides are an important material class for many opto-electronic devices such as displays, photovoltaic solar cells and light emitting diods (LEDs). The groups research is focussed on investigation novel TCO materials such as the new p-type transparent conducting oxide, Cr₂O₃:(Mg,N) found by us in 2011.

p-type TCOs

Our largest research project in the field of TCOs concerns hole conducting transparent (semi)conducting oxides. Such p-type TCOs are much sought after for fully transparent oxide electronics and can also help to improve efficiencies of solar cells and LEDs.

The performance of well known p-type TCOs is still rather poor. In the group we investigate a new, promising material based on Cr₂O₃. In particular we are interested in:

Doping and conduction mechanisms in p-type TCOs
Investigations of correlation of growth conditions to optical and electrical properties
Applications of p-type TCOs in organic photovoltaic solar cells
Fundamental investigations of interface formation in fully transparent p-n junctions

Modified n-type TCOs

We also investigate ways to modify some core properties of well known n-type TCOs such as SnO₂:F (FTO) and ZnO:Al (AZO) in terms of refractive index modifications, band gap engineering, and optical scattering properties (haze). Our work includes:

Elemental substitution to alter the optical properties of such TCOs
Investigations of novel layered structures for effective medium materials

TCO image

Illustration of the transparency and conductivity improvement of spray pyrolysis grown Cr₂O₃ once the precursor solution contains Magnesium and Nitrogen releasing species

Selected Publications

Title:Improving solar cell efficiency with optically optimised TCO layers
Authors:Fleischer, K.; Arca, E.; Shvets, I. V.
Source:Solar Energy Materials and Solar Cells, 101, p262 (2012)
TARA:Full text (Trinity open access repository)

Title:Effect of Chemical Precursors On the Optical and Electrical Properties of p-Type Transparent Conducting Cr₂O₃:(Mg,N)
Authors:Elisabetta Arca, Karsten Fleischer, Sergey A. Krasnikov, and Igor Shvets
Source:J. Phys. Chem. C 117, p21901 (2013)
TARA:Full text (Trinity open access repository)

Title:Spray pyrolysis growth of a high figure of merit, nano-crystalline, p-type transparent conducting material at low temperature
Authors:L. Farrell, E. Norton, B. J. O'Dowd, D. Caffrey, I. V. Shvets and K. Fleischer
Source:Appl. Phys. Lett. 107, 031901 (2015)