UCL Discovery Stage
UCL home » Library Services » Electronic resources » UCL Discovery Stage

2D Phase Purity Determines Charge-Transfer Yield at 3D/2D Lead Halide Perovskite Heterojunctions

Westbrook, RJE; Xu, W; Liang, X; Webb, T; Clarke, TM; Haque, SA; (2021) 2D Phase Purity Determines Charge-Transfer Yield at 3D/2D Lead Halide Perovskite Heterojunctions. Journal of Physical Chemistry Letters , 12 (13) pp. 3312-3320. 10.1021/acs.jpclett.1c00362. Green open access

[thumbnail of Westbrook_et_al_JPCL main manuscript_Symplectic.pdf]
Preview
Text
Westbrook_et_al_JPCL main manuscript_Symplectic.pdf - Accepted Version

Download (1MB) | Preview

Abstract

Targeted functionalization of 3D perovskite with a 2D passivation layer via R-NH3I treatment has emerged as an effective strategy for enhancing both the efficiency and chemical stability of ABX3 perovskite solar cells, but the underlying mechanisms behind these improvements remain unclear. Here, we assign a passivation mechanism where R-NH3I reacts with excess PbI2 in the MAPbI3 film and unsaturated PbI6 octahedra to form (R-NH3)2(MA)n–1PbnI3n+1. Crucially, we show that precise control of the 2D (R-NH3)2(MA)n–1PbnI3n+1 layer underpins performance improvements: n = 1 yields over a 2-fold improvement in hole injection to the HTL; n > 1 deteriorates hole injection. Ultrafast transient absorption spectroscopy suggests this n-dependence is rooted in the fact that fast (<6 ns) hole injection does not occur between the 3D and 2D layers. These results help explain contemporary empirical findings in the field and set out an important design rule for the further optimization of multidimensional perovskite optoelectronics.

Type: Article
Title: 2D Phase Purity Determines Charge-Transfer Yield at 3D/2D Lead Halide Perovskite Heterojunctions
Open access status: An open access version is available from UCL Discovery
DOI: 10.1021/acs.jpclett.1c00362
Publisher version: http://dx.doi.org/10.1021/acs.jpclett.1c00362
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Materials Science, Physics, SOLAR-CELL, CARRIER DYNAMICS, PASSIVATION, EFFICIENT, PERFORMANCE, PHOTOLUMINESCENCE, TOLERANCE, TRANSPORT, FILMS, LIMIT
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry
URI: https://discovery-pp.ucl.ac.uk/id/eprint/10130623
Downloads since deposit
1,440Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item