Universal passivation strategy to slot-die printed SnO2 for hysteresis-free efficient flexible perovskite solar module

Abstract

Perovskite solar cells (PSCs) have reached an impressive efficiency over 23%. One of its promising characteristics is the low-cost solution printability, especially for flexible solar cells. However, printing large area uniform electron transport layers on rough and soft plastic substrates without hysteresis is still a great challenge. Herein, we demonstrate slot-die printed high quality tin oxide films for high efficiency flexible PSCs. The inherent hysteresis induced by the tin oxide layer is suppressed using a universal potassium interfacial passivation strategy regardless of fabricating methods. Results show that the potassium cations, not the anions, facilitate the growth of perovskite grains, passivate the interface, and contribute to the enhanced efficiency and stability. The small size flexible PSCs achieve a high efficiency of 17.18% and large size (5 × 6 cm2) flexible modules obtain an efficiency over 15%. This passivation strategy has shown great promise for pursuing high performance large area flexible PSCs.

Triggering the Passivation Effect of Potassium Doping in Mixed‐Cation Mixed‐Halide Perovskite by Light Illumination

“…Figure 6a,b shows the normalized PL spectral evolution of 0 and 3.5 mol% K + perovskite films during the continuous excitation. [3,20,22] Without the presence of K + ions, as in the case of 0 mol% K + , minor halide substitution leads to the steady PL peak. By contrast, Figure 6b shows that the PL spectra of the 3.5 mol% K + perovskite undergo a broadening of FWHM and redshift of peak wavelength with increasing excitation time.…”

“…[1][2][3][4] The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has rapidly progressed from 3.8% to exceed 24.2% during the past decade. [1][2][3][4] The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has rapidly progressed from 3.8% to exceed 24.2% during the past decade.…”

“…[1][2][3][4] The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has rapidly progressed from 3.8% to exceed 24.2% during the past decade. [20] In this point of view, potassium cations are mainly distri buted at the surfaces and grain boundaries by forming KI/KBr to immobilize the surplus mobile halide ions and vacancies, [3] which is contradictory to the interstitial occupancy of K + in the perovskite lattice. Meanwhile, Abdi-Jalebi et al demonstrated that K + doping in mixed perovskites reduces nonradiative losses and photoinduced ion migration in perovskite films by decorating the surfaces and grain boundaries with passivating potassium halide layers.…”

Bifunctional Ytterbium (III) Chloride Driven Low‐Temperature Synthesis of Stable α‐CsPbI3 for High‐Efficiency Inorganic Perovskite Solar Cells

“…Figure c shows the V TFL of the 80 °C annealed perovskite film is 0.36 V, which is smaller than that of the 150 °C annealed sample (Figure d). The decreased V TFL indicates that the perovskite film with the adduct complex has a lower trap density . The trap densities of the perovskite film are reduced to 9.2 × 10 15 cm −3 from 2.7 × 10 16 cm −3 after introducing the adduct phase.…”

Laser‐Generated Nanocrystals in Perovskite: Universal Embedding of Ligand‐Free and Sub‐10 nm Nanocrystals in Solution‐Processed Metal Halide Perovskite Films for Effectively Modulated Optoelectronic Performance

“…[45] We thus assume the matched energy level accounts for the steady-state PL quenching, decreased PL lifetime, and the effective charge separation between perovskite and Cl-CDs, which is consistent with the devices modified by semiconductor molecules reported by Liu's group. [47] The decreased R ct suggests that the charge transfer at the perovskite/Sprio-OMeTAD becomes more efficient compared with the control device when the Cl-CDs are introduced, while the increased R rec reveals Cl-CDs passivation at GBs indeed decreases recombination of charge carriers in perovskite layer. [46] The electron mobility is found to be 0.019 and 0.248 cm 2 V −1 s −1 for the control and CsFAMA-Cl-CDs, respectively, consistent with faster charge extraction observed from TRPL measurements.…”