Retarding charge recombination in perovskite solar cells using ultrathin MgO-coated TiO2 nanoparticulate filmsElectronic supplementary information (ESI) available: Representative photovoltaic characteristic values for each solar cell, standard deviations of photovoltaic properties, HR-TEM images of MgO thickness on TiO2 nanoparticles as a function of magnesium methoxide concentration, and J-V characteristics for the best performance cells. See DOI: 10.1039/c4ta03684k

• Main Authors: Han, Gill Sang, Chung, Hyun Suk, Kim, Byeong Jo, Kim, Dong Hoe, Lee, Jin Wook, Swain, Bhabani Sankar, Mahmood, Khalid, Yoo, Jin Sun, Park, Nam-Gyu, Lee, Jung Heon, Jung, Hyun Suk
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c4ta03684k

MgO-coated TiO 2 nanoparticle (NP)-based electron collecting layers were fabricated to prevent charge recombination at the methylamine lead iodide/TiO 2 interface in perovskite solar cells. The open circuit voltage ( V oc ) and fill factor (ff) of perovskite solar cells based on MgO-coated TiO 2 charge collectors were 0.89 V and 71.2%, respectively. These values were 4.7% and 6.1% higher than the pure TiO 2 based perovskite solar cells. Transient photovoltage decay data exhibited recombination times for MgO-coated TiO 2 NP-based perovskite solar cells about three times longer than those of TiO 2 NP based solar cells. The longer recombination time was responsible for enhancing the V oc and ff of MgO-coated TiO 2 NP-based perovskite solar cells. By employing a MgO nanolayer, we observed that the power conversion efficiency (PCE) was increased from 11.4% to 12.7%, demonstrating that MgO ultrathin nanolayers are able to efficiently retard charge recombination in perovskite solar cells. MgO ultrathin nanolayers are able to efficiently retard charge recombination in perovskite solar cells.