We report the fabrication of solution-processed In2O3 and In2O3/ZnO heterojunction thin-film transistors (TFTs) where the precursor materials were converted to their semiconducting state using high power light pulses generated by a xenon flash lamp. In2O3 TFTs prepared on glass substrates exhibited low-voltage operation (≤2 V) and a high electron mobility of ∼6 cm2 V−1 s−1. By replacing the In2O3 layer with a photonically processed In2O3/ZnO heterojunction, we were able to increase the electron mobility to 36 cm2 V−1 s−1, while maintaining the low-voltage operation. Although the level of performance achieved in these devices is comparable to control TFTs fabricated via thermal annealing at 250 °C for 1 h, the photonic treatment approach adopted here is extremely rapid with a processing time of less than 18 s per layer. With the aid of a numerical model we were able to analyse the temperature profile within the metal oxide layer(s) upon flashing revealing a remarkable increase of the layer's surface temperature to ∼1000 °C within ∼1 ms. Despite this, the backside of the glass substrate remains unchanged and close to room temperature. Our results highlight the applicability of the method for the facile manufacturing of high performance metal oxide transistors on inexpensive large-area substrates.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors would like to thank Kurt A. Schroder and John Passiak from Novacentrix for the access to SimPulse in order to carry out all relevant simulations in this study. This work was funded by the People Programme (Marie Curie Actions) of the European Union's Framework Programme Horizon2020: “Flexible Complementary Hybrid Integrated Circuits” (FlexCHIC), grant agreement no. 658563. D. J. P. acknowledges support from the Royal Society for his University Research Fellowship (No. UF100105). D. J. P. and A. R. acknowledge support from the EPSRC (EP/M028291/1).