Vitamin Natural Molecule Enabled Highly Efficient and Stable Planar n–p Homojunction Perovskite Solar Cells with Efficiency Exceeding 24.2%

Abstract

The defect passivation and interface energetics‐modification between perovskite and transport layers are significant for the further improvement of efficiency and stability of perovskite solar cells (PSCs). Here, a double‐layer modification engineering strategy is employed by different functionalized natural vitamins into the electron transport layer and perovskite, respectively. Considering the different role of each functional layer in PSCs, the vitamin C (VC) with high conductivity is introduced into SnO2, showing electron mobility enhancement, an interface energy‐levels offsets reduction, and enhanced interfacial charge transfer. Meanwhile, antioxidant vitamin D2 (VD2) with multiple passivating functional groups is introduced into the perovskite bulk to moderately tailor its intrinsic characteristics. The surface energetics of perovskite are changed from n‐type to p‐type, the thickness of the p‐type perovskite is 80 nm, thus the spontaneous n–p homojunction is formed in perovskite caused by VD2, which increases the built‐in electric field and the efficiency of perovskite hole extraction. The synergistic effect of VC and VD2 better heightens the charge extraction efficiency and achieves charge‐carrier transport balance in PSCs. The optimum device achieves a power conversion efficiency of 24.20% and a fill factor of 81.01% with negligible hysteresis. This efficiency is among the best PSCs employing natural molecules reported so far.

Application of Natural Molecules in Efficient and Stable Perovskite Solar Cells

“…Liu and co-authors introduced vitamin D2 (VD2) into the perovskite bulk [ 34 ], and 530 meV of the WF relative to the vacuum energy level ( E VAC ) increased, while the E F and VBM shifted from 1.09 to 0.51 eV, which indicated that the surface energetics transformed from n-type to p-type. KPFM exhibited that the thickness of the n–p homojunction formed accounts for about 80 nm.…”

“…Copyright 2021, Elsevier. ( g ) Energy-level alignment schematics of the PSC comprising VD2 and VC [ 34 ]. Copyright 2022, Wiley-VCH.…”

Multifunctional Aminoglycoside Antibiotics Modified SnO2 Enabling High Efficiency and Mechanical Stability Perovskite Solar Cells

“…Moreover, vitamin C-modified SnO 2 offered a favorable energy level arrangement between SnO 2 and perovskite films so that enhanced interfacial charge transfer. [21] Liu et al used KPF 6 to modify the SnO 2 /perovskite interface, in which PF 6 − could chemically link the SnO 2 layer and perovskite layer via coordination bond and hydrogen bond respectively, and thus improving interfacial contact and releasing interfacial stress. [22] Wang et al incorporated HEPES into SnO 2 , as a result, the conduction band (CB) edges of SnO 2 and perovskite layer became well matched.…”

Self‐Healing Perovskite Grain Boundaries in Efficient and Stable Solar Cells via Incorporation of 502 Adhesive

“…To date, some additives extracted from nature have been adopted as effective passivation agents for enhanced PSCs, such as caffeine, [ 19 ] theophylline, [ 20 ] lycopene, [ 21 ] and vitamin. [ 22 ] The scientific innovation may be inspired by our daily life. 502 adhesive is a fast‐drying agent, which can bond a wide variety of materials, such as steel, nonferrous metals, rubber, leather, ceramics, wood, and glass.…”

“…[18] To date, some additives extracted from nature have been adopted as effective passivation agents for enhanced PSCs, such as caffeine, [19] theophylline, [20] lycopene, [21] and vitamin. [22] The scientific innovation may be inspired by our daily life. 502 Additive engineering has become an effective method to passivate the grain boundary defects of perovskite films for enhanced photovoltaic performance.…”