Modifications in structural morphology of CH3NH3PbI3 perovskite using nitrilotriacetic acid and glycine as habit modifiers

Abstract

In this article, we have studied the effect of two well-known habit modifiers nitrilotriacetic acid (NTA) and glycine on structural morphology and growth of methylammonium lead iodide (MAPbI3). We found that the addition of a small amount of NTA or glycine to the precursor solution modulated the crystal growth of MAPbI3, producing sub-millimeter sized cuboidal crystals of MAPbI3 with structural morphology suitable for close packing in thin films. The NTA or glycine is soluble additive which gets adsorbed on selective crystallographic faces and retard their growth rate, thereby influencing the final structural morphology of the crystals. Thin films are prepared using precursor solutions containing 1.0 wt% of NTA or glycine. These films were characterized using different characterization techniques. We observed that these additives modify the structural morphology of MAPbI3 crystals from irregular to cuboidal shape. It also results modifications in its optical properties without changing the crystal structure.