Methods for Perovskite Device Processing by Vapor Transport Deposition

A method of forming a perovskite precursor layer comprising:

• providing a substrate stack in a deposition chamber, the substrate stack having a first charge transport layer on an electrode;
• depositing a first perovskite-forming composition on the substrate stack in the deposition chamber by a vapor transport deposition (VTD) process, comprising:
• heating a source material to a temperature in a range of 375° C. to 550° C., wherein the source material is a metal halide;
• providing a vapor curtain to direct vapor of the source material using a carrier gas toward the substrate stack in the deposition chamber, wherein the vapor curtain has a width greater than 1 meter, the deposition chamber having a pressure in a range of 0.1 to 2.0 Torr;
• and
• forming the precursor layer, at a deposition rate in a range of 0.01 to 1.50 μm per minute, to a thickness of 100-2000 nm, wherein the precursor layer comprises a plurality of metal halide crystal grain structures, wherein the plurality of metal halide crystal grain structures of the precursor layer form a crystal matrix having a porosity in a range from 35% to 65%.

An intermediate structure for a perovskite photovoltaic device, comprising:

• a substrate stack, comprising a first electrode over a substrate, and a first charge transport layer over the first electrode;
• and
• a precursor layer over the first charge transport layer;
• wherein:
• the precursor layer has a thickness in a range of 100 nm to 2000 nm, and
• the precursor layer comprises a plurality of metal halide crystal grain structures, wherein the plurality of metal halide crystal grain structures form a crystal matrix having a porosity in a range from 35% to 65%.