Stability ascent in perovskite solar cells employing star poly(3-hexylthiophene)/quantum dot nanostructures

Abstract

Half-star poly(3-hexylthiophene) (P3HT)/carbon quantum dot (CQD) and star P3HT/graphene quantum dot (GQD) supramolecules were constructed from crystallization of P3HT chains onto CQD and GQD nanoparticles, respectively. These nano-hybrids not only promoted the morphological parameters in upon-constructed state (594 and 612 nm), but also retained them during 150 day air aging as far as feasible (415 and 523 nm). The pure QDs were not capable of inducing crystallinity and improving morphology in CH 3 NH 3 PbI 3 layers, instead, they froze perovskite precursors and decreased rate of degradation during aging. Forwardly, star P3HT/GQD and half-star P3HT/CQD supramolecules simultaneously promoted efficacy and stability of perovskite solar cells. The best short circuit current density (J sc = 24.71 and 21.94 mA/cm 2 ), fill factor (FF = 77 and 75%), open circuit voltage (V oc = 0.96 and 0.94 V) and power conversion efficiency (PCE = 18.27 and 15.47%) were acquired for photovoltaics based on star and half-star nanostructures. The pre-designed supramolecules could perfectly interact with CH 3 NH 3 PbI 3 constituents and decelerate the degradation of crystalline perovskite areas during long-term air aging procedures by freezing morphology of active layers. PCE of perovskite + star P3HT/GQD and perovskite + half-star P3HT/CQD devices only decreased from 18.27 to 9.57% as well as from 15.47 to 5.84%, respectively, within 150 days air aging. In this aging duration, the performance of unmodified CH 3 NH 3 PbI 3 photovoltaics was plummeted from 10.77 to zero%. Star and half-star nano-hybrids also made a prominent progress in charge transportation even during long-term air agings. • Half-star P3HT/CQD and star P3HT/GQD supramolecules were constructed. • Nano-hybrids not only promoted morphology in upon-constructed state, but also retained them during - aging. • The best J sc , FF, V oc and PCE were acquired for photovoltaics by star and half-star nanostructures. • Supramolecules interact with CH 3 NH 3 PbI 3 and decelerate the degradation of crystalline perovskite during long-term aging.