Static and dynamic study of interfaces and grain boundaries in solution processed halide perovskite based advanced energy conversion systems
EMSL Project ID
49412
Abstract
Advanced energy conversion systems that meet global demands present a formidable goal for a sustainable future. Renewables resources are underexploited, and warrant further research to exploit their full potential. Solar energy is one of the most promising technologies due its relative abundance and its ability to match global energy needs. But the high cost of silicon-based solar cells has spurred research in new directions. Amongst the next generation of solar cells, hybrid organic-inorganic halide perovskites show the most promise for commercialization due to their low temperature solution processed techniques while maintaining high efficiencies of ~ 20 %, but the long term stability of such cells is currently poor. This requires research directed toward better understanding the device structure-property relationships, which are a direct result of solvent mediated growth processes. Grain boundaries and interfaces in these devices are the major bottlenecks for achieving longer operating lifetimes, and a detailed study will enable us to better understand and engineer stable perovskite solar cells. The ability of the halide perovskite based devices to maintain high efficiencies using a solvent engineering approach point to an intricate solute-solvent interaction during the growth of the film, which will affect the formation of grain boundaries and their subsequent interaction with moisture. The interface between the halide perovskite and the hole transport layer (which contain organic species) is more complex. Liquid additives in the hole transport layer such as tBP (tert-butyl pyridine) are able to dissolve the reactant species, leading to a solid-liquid interface trapped in a solid state device. Our group has observed that the additives in the hole transport layer significantly affect its morphology and ultimately the device stability.
We wish to gain a nano-scale understanding of how this solid-liquid interface at the boundary of the halide perovskite layer and the hole transport layer interacts with moisture. Combining a static study using atom probe tomography (APT) and a dynamic in-situ study using a liquid flow cell TEM will provide a comprehensive picture in real time of the various interactions involved, ultimately leading to the development of more resilient perovskite solar cells.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2016-10-01
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members