Ti1–graphene single-atom material for improved energy level alignment in perovskite solar cells

Abstract

Carbon-based perovskite solar cells (C-PSCs) are widely accepted as stable, cost-effective photovoltaics. However, C-PSCs have been suffering from relatively low power conversion efficiencies (PCEs) due to severe electrode-related energy loss. Herein, we report the application of a single-atom material (SAM) as the back electrode in C-PSCs. Our Ti1/rGO consists of single titanium (Ti) adatoms anchored on reduced graphene oxide (rGO) in a welldefined Ti1O4-OH configuration capable of well tuning the electronic properties of rGO. The downshift of the Fermi level notably minimizes the series resistance of the carbon-based electrode. By combining with an advanced modular cell architecture, a steady-state PCE of up 2 to 20.6% for C-PSCs is finally achieved. Furthermore, the device without encapsulation tracked at the maximum power point under one-sun illumination retains 90% of its initial value after 1000 h.the devices without encapsulation retain 98% and 95% of their initial values for 1300 h under 1-sun illumination at 25 o C and 60 o C, respectively.

Rear Electrode Materials for Perovskite Solar Cells

“…Reproduced with permission. [ 82 ] Copyright 2021, Springer Nature. g) Device configuration and schematic diagram of BTA anticorrosion.…”

“…reported a SAM of Ti 1 –reduced graphene oxide (rGO) consisting of single titanium (Ti) atoms anchored by surface oxygen atoms on the rGO in a well‐defined configuration as the back electrode in PSCs. [ 82 ] Finally, a steady‐state PCE of up to 20.6% for C‐PSCs was achieved. Furthermore, the devices without encapsulation retained 98% and 95% of their initial values for 1300 h under 1 sun of illumination at 25 and 60 °C, respectively.…”

“…Reproduced with permission. [82] Copyright 2021, Springer Nature. initial efficiency is retained after 1000 h storage under ambient conditions.…”

“…f) The best long-term stability of the device with double-layer HTL tested at 60-65 °C under metal-halide lamps (83 mW cm −2 ) in reverse direction. Reproduced with permission [82]. Copyright 2021, Springer Nature.…”

A Universal Single‐Atom Coating Strategy Based on Tannic Acid Chemistry for Multifunctional Heterogeneous Catalysis

“…Benefiting from the distinctive active site and adjustable local bonding environment, single-atom catalysts open avenues to understand and modulate the catalytic transformation at the molecular level. [2] Therefore, singleatom catalysts are expanding beyond catalysis, and are sparking new applications such as sensors, [3] tumor therapy, [4] water treatment, [5] batteries, [6] and photovoltaic devices, [7] in which molecule activation is required. The new applications require single-atom catalysts coated on different substrates or hybrids with other materials to achieve target function.…”