Since 2009, much progress has been made in perovskite solar cells. The perovskite light absorber methylammonium lead iodide (MAPbI3), can be made from inexpensive precursors, effectively separates charge carriers, and leads to devices with power-conversion efficiencies greater than 16%. In this work, we focus on the integration of &lt;001&gt; oriented anatase TiO2 films into the solar cell heterostructure. Titanium dioxide is a key component of the solar cell that serves as blocking and electron transport layers (ETL). The typical ETL is composed of amorphous or randomly oriented nanocrystalline TiO2. However, oriented thin films should improve charge carrier separation and collection. To construct our solar cells we spin-coat MAPbI3 onto &lt;001&gt; oriented anatase TiO2 thin films. The hole transport layer (HTL), spiro-OMeTAD, is deposited onto the MAPbI3 layer. We have studied the effectiveness of charge transport to TiO2 and the HTM by photoluminescence (PL) spectroscopy. It was observed that PL intensity of perovskite—TiO2 heterojunction decreases by 54% when TiO2 is annealed under H2 compared to MAPbI3 without an ETL. The PL intensity is further decreased in the presence of the HTM. The Bragg diffraction pattern of the perovskite thin film suggests that the MAPbI3 exhibits preferred orientation in the presence of &lt;001&gt; textured TiO2 which may improve carrier separation and overall device efficiency. The MAPbI3 prepared by a 2-step deposition method was compared to pre-made perovskite and found to have better stability in ambient air. Since grain size and orientation of CH3NH3PbI3 play an important role in the effectiveness of a solar cell, future work will involve fine tuning the deposition of perovskite in order to create efficient solar cells.

Integration of <001> oriented anatase TiO2 electron transport layer into perovskite solar cells to improve carrier separation

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.