Mesoscopic CH₃NH₃PbI₃/TiO₂Heterojunction Solar Cells

TLDR

The authors present the first hole‑conductor‑free mesoscopic CH₃NH₃PbI₃/TiO₂ heterojunction solar cell fabricated by depositing perovskite nanoparticles from a CH₃NH₃I/PbI₂ solution onto a 400‑nm TiO₂ nanosheet film. Perovskite nanoparticles were deposited from a γ‑butyrolactone solution onto the TiO₂ film, followed by evaporation of a gold back contact. The resulting device achieves a short‑circuit current of 16.1 mA cm⁻², an open‑circuit voltage of 0.631 V, a fill factor of 0.57, and a power‑conversion efficiency of 5.5 % under AM 1.5 (1000 W m⁻²) illumination, rising to 7.3 % at 100 W m⁻², demonstrating that the perovskite nanoparticles serve simultaneously as light absorber and hole conductor for low‑cost, high‑efficiency solar cells.

Abstract

We report for the first time on a hole conductor-free mesoscopic methylammonium lead iodide (CH(3)NH(3)PbI(3)) perovskite/TiO(2) heterojunction solar cell, produced by deposition of perovskite nanoparticles from a solution of CH(3)NH(3)I and PbI(2) in γ-butyrolactone on a 400 nm thick film of TiO(2) (anatase) nanosheets exposing (001) facets. A gold film was evaporated on top of the CH(3)NH(3)PbI(3) as a back contact. Importantly, the CH(3)NH(3)PbI(3) nanoparticles assume here simultaneously the roles of both light harvester and hole conductor, rendering superfluous the use of an additional hole transporting material. The simple mesoscopic CH(3)NH(3)PbI(3)/TiO(2) heterojunction solar cell shows impressive photovoltaic performance, with short-circuit photocurrent J(sc)= 16.1 mA/cm(2), open-circuit photovoltage V(oc) = 0.631 V, and a fill factor FF = 0.57, corresponding to a light to electric power conversion efficiency (PCE) of 5.5% under standard AM 1.5 solar light of 1000 W/m(2) intensity. At a lower light intensity of 100W/m(2), a PCE of 7.3% was measured. The advent of such simple solution-processed mesoscopic heterojunction solar cells paves the way to realize low-cost, high-efficiency solar cells.