Widely applicable phosphomolybdic acid doped poly(9-vinylcarbazole) hole transport layer for perovskite light-emitting devices

In this paper, a cross-linked poly(9-vinylcarbazole) (PVK):phosphomolybdic acid (PMA) layer is used as the hole transport layer in perovskite light-emitting devices, and the morphology, crystal structure, and photophysical properties of perovskite films on the PVK:PMA layer are studied. The addition of PMA into the PVK layer improves the perovskite morphology integrity and promotes hole transport. As a result, perovskite light-emitting devices using a PVK:PMA hole transport layer exhibit an improved maximum luminous efficiency of 22.1 cd A−1 and power efficiency of 18.2 lm W−1 when compared with those of the counterparts with a PVK hole transport layer. Efficient perovskite light-emitting devices can be accessed by using various antisolvents due to the good solvent resistance of PVK:PMA networks. Moreover, the luminous efficiencies of perovskite light-emitting devices with a PVK:PMA hole transport layer are almost invariant irrespective of the presence of a hole injection layer, illustrating wide applicability of the PVK:PMA hole transport layer in perovskite light-emitting devices.