Provided herein are perovskite-polymer films, methods of forming polymer-perovskite films, and devices including polymer-perovskite films. The polymer-perovskite films may include a plurality of methylammonium lead chloride (CH3NH3PbCl3) nanopillar crystals embedded in a polymer matrix. The devices can be optoelectronic devices, such as light emitting diodes, which include polymer-perovskite films. The polymer-perovskite films of the devices can be hole transport layers in the devices. The methods of making films may include spin casting a precursor solution followed by thermal annealing.