Publication Details

Malgras, V., Zhang, G., Nattestad, A., Clarke, T. M., Mozer, A. J., Yamauchi, Y. & Kim, J. (2015). Trap-assisted transport and non-uniform charge distribution in sulphur-rich PbS colloidal quantum dot-based solar cells with selective contacts. ACS Applied Materials and Interfaces, 7 (48), 26455-26460.


This study reports evidences of dispersive transport in planar PbS colloidal quantum dots heterojunction-based devices as well as the effect of incorporating a MoO3 hole selective layer on the charge extraction behavior. Steady state and transient characterization techniques are employed to determine the complex recombination processes involved in such devices. The addition of a selective contact drastically improves the device efficiency up to 3.15 % (especially through the photocurrent and series resistance) and extends the overall charge lifetime by suppressing the main first-order recombination pathway observed in device without MoO3. The lifetime and mobility calculated for our sulphur-rich PbS-based devices are similar to previously reported values in lead-rich quantum dots-based solar cells. Nevertheless, strong Shockley-Read-Hall mechanisms appears to keep restricting charge transport, the equilibrium voltage taking more than 1 ms to be established.

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