%0 Journal Article %1 park2018understanding %A Park, Byung-wook %A Kedem, Nir %A Kulbak, Michael %A Lee, Do Yoon %A Yang, Woon Seok %A Jeon, Nam Joong %A Seo, Jangwon %A Kim, Geonhwa %A Kim, Ki Jeong %A Shin, Tae Joo %A Hodes, Gary %A Cahen, David %A Seok, Sang Il %D 2018 %J Nature Communications %K diffusion_length excess_lead_iodid perovskite %N 1 %P 3301-- %R 10.1038/s41467-018-05583-w %T Understanding how excess lead iodide precursor improves halide perovskite solar cell performance %U https://doi.org/10.1038/s41467-018-05583-w %V 9 %X The presence of excess lead iodide in halide perovskites has been key for surpassing 20% photon-to-power conversion efficiency. To achieve even higher power conversion efficiencies, it is important to understand the role of remnant lead iodide in these perovskites. To that end, we explored the mechanism facilitating this effect by identifying the impact of excess lead iodide within the perovskite film on charge diffusion length, using electron-beam-induced current measurements, and on film formation properties, from grazing-incidence wide-angle X-ray scattering and high-resolution transmission electron microscopy. Based on our results, we propose that excess lead iodide in the perovskite precursors can reduce the halide vacancy concentration and lead to formation of azimuthal angle-oriented cubic α-perovskite crystals in-between 0° and 90°. We further identify a higher perovskite carrier concentration inside the nanostructured titanium dioxide layer than in the capping layer. These effects are consistent with enhanced lead iodide-rich perovskite solar cell performance and illustrate the role of lead iodide.

@article{park2018understanding, abstract = {The presence of excess lead iodide in halide perovskites has been key for surpassing 20% photon-to-power conversion efficiency. To achieve even higher power conversion efficiencies, it is important to understand the role of remnant lead iodide in these perovskites. To that end, we explored the mechanism facilitating this effect by identifying the impact of excess lead iodide within the perovskite film on charge diffusion length, using electron-beam-induced current measurements, and on film formation properties, from grazing-incidence wide-angle X-ray scattering and high-resolution transmission electron microscopy. Based on our results, we propose that excess lead iodide in the perovskite precursors can reduce the halide vacancy concentration and lead to formation of azimuthal angle-oriented cubic α-perovskite crystals in-between 0° and 90°. We further identify a higher perovskite carrier concentration inside the nanostructured titanium dioxide layer than in the capping layer. These effects are consistent with enhanced lead iodide-rich perovskite solar cell performance and illustrate the role of lead iodide.}, added-at = {2018-09-05T14:07:14.000+0200}, author = {Park, Byung-wook and Kedem, Nir and Kulbak, Michael and Lee, Do Yoon and Yang, Woon Seok and Jeon, Nam Joong and Seo, Jangwon and Kim, Geonhwa and Kim, Ki Jeong and Shin, Tae Joo and Hodes, Gary and Cahen, David and Seok, Sang Il}, biburl = {https://www.bibsonomy.org/bibtex/2be3bf33635cde765a74487394e39192b/bretschneider_m}, doi = {10.1038/s41467-018-05583-w}, interhash = {7113b90a5ea68cc662681f9036c34ab3}, intrahash = {be3bf33635cde765a74487394e39192b}, issn = {20411723}, journal = {Nature Communications}, keywords = {diffusion_length excess_lead_iodid perovskite}, number = 1, pages = {3301--}, refid = {Park2018}, timestamp = {2018-09-05T14:07:14.000+0200}, title = {Understanding how excess lead iodide precursor improves halide perovskite solar cell performance}, url = {https://doi.org/10.1038/s41467-018-05583-w}, volume = 9, year = 2018 }