We develop and synthesise new semiconductor materials, and characterise them using a modern toolbox of materials chemistry: X-Ray and electron diffraction, solid-state NMR, electron microscopy and optical spectroscopies. A particularly unique aspect is the development of multimodal techniques to interrelate a series of different measurements to provide connections between the materials’ chemical, physical, optical, morphological and structural properties – where possible on the same local scan area.[1,2,3] Recent work has focused on pushing new nano-structured emitters further into the blue spectral region, and molecular modulation/passivation protocols for different bandgap bulk halide perovskites to increase their performance and long-term device stability. In our pursuit for new synthetic approaches of optoelectronic materials, we also make use of numerical approaches, such as finite element modelling, to design reactor systems leading to optimal throughput and yield. Beyond materials chemistry, we develop new solid-state NMR protocols to characterise the atomic-level microstructure of complex materials with higher sensitivity and resolution [5]. We also employ a number of advanced diffraction-based techniques at the Diamond Light Source synchrotron, making use of beamlines I07 for Grazing-Incidence Wide-Angle X-Ray Spectroscopy (GIWAXS) and I14 for local scanning nano-probe measurements to further understand material and device behaviour.
[1] Tennyson, E. M.; Doherty, T. A. S.; *Stranks, S. D. Heterogeneity at multiple length scales in halide perovskite semiconductors, Nature Reviews Materials, 2019, https://doi.org/10.1038/s41578-019-0125-0
[2] Doherty, T. A. S.; Winchester, A, J.; Macpherson, S. M.; Johnstone, D. N.; Pareek, V.; Tennyson E. M.,; Kosar, S.; Kosasih, F. U.; Anaya, M.; Abdi-Jalebi, M.; Andaji-Garmaroudi, Z.; Wong, E. L.; Madéo, J.; Chiang, Y.-H.; Park, J.-S.; Jung, Y.-K.; Petoukhoff, E. C.; Divitini, G.; Man, M. K. L.; Ducati, C.; Walsh, A.; Midgley, P. A.; *Dani, K.; *Stranks, S. D. Visualising Performance-Limiting Nanoscale Trap Clusters at Grain Junctions in Halide Perovskites Nature 2020, DOI: 10.1038/s41586-020-2184-1
[3] Jones, T. W.; Osherov, A.; Alsari, M.; Sponseller, M.; Duck, B. C.; Jung, Y.-K.; Settens, C.; Niroui, F.; Brenes, R.; Stan, C. V.; Li, Y.; Abdi-Jalebi, M.; Tamura, N.; Macdonald, J. E.; Burghammer, M.; Friend, R. H.; Bulovic, V.; Walsh, A.; Wilson, G. J.; Lilliu, S.; *Stranks, S. D. Lattice strain causes non-radiative losses in halide perovskites, Energy Environ. Sci., 2019, 12, 596-606
[4] Hoye, R. L. Z.; Lai, M-L.; Anaya, M.; Tong, Y.; Galkowski, K.; Doherty, T.; Li, W.; Huq T. N.; Mackowski, S.; Polavarapu, L.; Feldmann, J.; MacManus-Driscoll, J. L.; Friend, R. H.; Urban, A. S.; *Stranks, S. D. Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes ACS Energy Lett., 2019, 4, 1181-1188
[5] Kubicki, D. J.; Prochowicz, D.; Salager, E.; Rakhmatullin, A.; *Grey, C. P.; *Emsley, L.; *Stranks, S. D. Local Structure and Dynamics in Methylammonium, Formamidinium and Cesium Tin(II) Mixed-Halide Perovskites from 119Sn Solid-State NMR J. Am. Chem. Soc. 2020, DOI: 10.1021/jacs.0c00647