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Abstract
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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 CH3NH3PbI3 layers, instead, they
froze perovskite precursors and decreased rate of degradation during aging. Forwardly, star P3HT/GQD and halfstar P3HT/CQD supramolecules simultaneously promoted effcacy and stability of perovskite solar cells. The best
short circuit current density (Jsc = 24.71 and 21.94 mA/cm2), fll factor (FF = 77 and 75%), open circuit voltage
(Voc = 0.96 and 0.94 V) and power conversion effciency (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 CH3NH3PbI3 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 unmodifed CH3NH3PbI3 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.
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