Passivating defects leads to record performance of WSe2

© K. Sivula / EPFL 2017

© K. Sivula / EPFL 2017

Addressing defects is the key to high performance in solution-processed semiconducting 2D WSe2. In a new paper we report a combined strategy and benchmark results.

The direct storage or solar energy in chemical bonds is possible via water photo-reduction into hydrogen but inexpensive, stable and high performance photocathodes are needed. Solution-processed 2D WSe2 represents a promising material for this application, and has been demonstrated previously by our group. However, the defects present in the exfoliated 2D nano-flakes have presented high performance solar energy conversions. In our latest report by Xiaoyun Yu et al. we demonstrate that a two-step strategy to passivate both internal defects and edge defects can greatly enhance WSe2 photocathodes for solar hydrogen production increasing the performance by a factor of 4 over previous results and bringing this technology one step closer to practical application. Check out our report in the journal Nano Letters