Youcheng Zhang1,2,Amita Ummadisingu1,Henning Sirringhaus1
Cavendish Laboratory, Department of Physics, University of Cambridge1,University of Cambridge2
Youcheng Zhang1,2,Amita Ummadisingu1,Henning Sirringhaus1
Cavendish Laboratory, Department of Physics, University of Cambridge1,University of Cambridge2
Organic-inorganic halide perovskites (OIHPs) have exhibited promising optoelectronic properties as the next-generation solar cells and light-emitting diodes despite their ionic nature. Early reports on perovskite field-effect transistors (FETs) showed the device performance was greatly affected by ion migration around room temperature<sup>[1,2]</sup>. Through accurate modification techniques on surface and composition, recent reports on perovskite FETs have effectively suppressed ion migration and shown excellent field-effect mobility values around 1 cm<sup>2</sup>/Vs <sup>[3–6]</sup> with good stability and low hysteresis. Despite the progress, we still lack a detailed understanding of how ion migration leads to the instabilities in the characteristics of perovskite FETs. In this study, we systematically investigated device instabilities as a function of the film composition and defect density in Cs<sub>0.05</sub>MA<sub>0.78</sub>FA<sub>0.17</sub>PbI<sub>3</sub>. By deliberately turning the film stoichiometry from perfect to imperfect, we precisely analysed the development of non-idealities in the transfer characteristics. The defect migration dynamics in the FET devices were further investigated by ex-situ photoluminescence (PL) mapping. Correlating charge transport measurement with PL mapping result, we obtained a full picture of how defect motion leads to anomalous transport behaviours in FETs. Our study provides a detailed understanding of the disturbance effect of defect migration on charge carrier transport in OIHPs.<br/><b>References</b><br/>[1] J. G. Labram, D. H. Fabini, E. E. Perry, A. J. Lehner, H. Wang, A. M. Glaudell, G. Wu, H. Evans, D. Buck, R. Cotta, L. Echegoyen, F. Wudl, R. Seshadri, M. L. Chabinyc, <i>J. Phys. Chem. Lett.</i> <b>2015</b>, <i>6</i>, 3565–3571.<br/>[2] X. Y. Chin, D. Cortecchia, J. Yin, A. Bruno, C. Soci, <i>Nat. Commun.</i> <b>2015</b>, <i>6</i>, 7383.<br/>[3] X.-J. J. She, C. Chen, G. Divitini, B. Zhao, Y. Li, J. Wang, J. F. Orri, L. Cui, W. Xu, J. Peng, S. Wang, A. Sadhanala, H. Sirringhaus, <i>Nat. Electron.</i> <b>2020</b>, <i>3</i>, 694–703.<br/>[4] S. P. Senanayak, M. Abdi-Jalebi, V. S. Kamboj, R. Carey, R. Shivanna, T. Tian, G. Schweicher, J. Wang, N. Giesbrecht, D. Di Nuzzo, H. E. Beere, P. Docampo, D. A. Ritchie, D. Fairen-Jimenez, R. H. Friend, H. Sirringhaus, <i>Sci. Adv.</i> <b>2020</b>, <i>6</i>, 1–13.<br/>[5] S. Jana, E. Carlos, S. Panigrahi, R. Martins, E. Fortunato, <i>ACS Nano</i> <b>2020</b>, <i>14</i>, 14790–14797.<br/>[6] H. P. Kim, M. Vasilopoulou, H. Ullah, S. Bibi, A. E. Ximim Gavim, A. G. Macedo, W. J. da Silva, F. K. Schneider, A. A. Tahir, M. A. Mat Teridi, P. Gao, A. R. bin M. Yusoff, M. K. Nazeeruddin, <i>Nanoscale</i> <b>2020</b>, <i>12</i>, 7641–7650.