Bilayer SnO₂ as Electron Transport Layer for Highly Efficient Perovskite Solar Cells

Abstract

Tin oxide (SnO 2 ) has been reported as a promising electron transport layer (ETL) for planar heterojunction perovskite solar cells (PSCs). This work reports a low temperature solution-processed bilayer SnO 2 as an efficient ETL in gas-quenched planar-heterojunction methylammonium lead iodide (MAPbI 3 ) perovskite solar cells. SnO 2 nanoparticles were employed to fill the pin-holes of sol−gel SnO 2 layer and form a smooth and compact bilayer structure. The PCE of bilayer devices has increased by 30% compared with sol− gel reference device and the J sc , V oc , and FF has been improved simultaneously. The superior performance of bilayer SnO 2 is attributed to the reduced current leakage, enhanced electron extraction characteristics, and mitigated the trapassisted interfacial recombination via X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and space-charge limited current−voltage (SCLC) analysis.

Low‐Temperature‐Processed WOx as Electron Transfer Layer for Planar Perovskite Solar Cells Exceeding 20% Efficiency

“…Dark J–V curves are shown in Figure d. While both PSCs with B‐WO x and H‐WO x ETLs show low leakage current density, the steeper current increase at high bias voltage (larger than 0.8 V) for the solar cell based on H‐WO x reveals its most efficient electron injection capability . Last but not least, H‐WO x is most compatible with perovskites, as mentioned previously.…”

Boosting the Efficiency of SnO2‐Triple Cation Perovskite System Beyond 20% Using Nonhalogenated Antisolvent

“…Figure d presents the dark Nyquist plots of pure EA and EA + 30% Hex representative devices and the corresponding equivalent circuits employed to analyze the data. The equivalent circuit is made of different components that are associated with different electronic parameters of the device, specifically: i) R s , the series resistance arising from the metal and wire connection, ii) R c , the contact resistance at the ETL/perovskite or perovskite/HTL interface, iii) R rec , the carrier recombination resistance, iv) C c , the chemical capacitance and v) C µ , the chemical/bulk capacitance of the device . It should be noted that C c and C µ capacitive elements were included in the equivalent circuit to enable a better fit.…”

Chlorine‐modified SnO2 electron transport layer for high‐efficiency perovskite solar cells

“…It has attracted tremendous research efforts for its high transmittance, suitable bandgap, matched energy level, high electron mobility, and low temperature preparation. Significant efforts have been devoted to developing highly efficient PSCs by utilizing a SnO 2 ETL . Thus far, the certified efficiency of cells with a SnO 2 ETL has reached 23.3%, the highest efficiency for the planar‐type PSCs reported to date; however, based on the Shockley‐Queisser theory, the theoretical PCE limit is 30.5%.…”

“…Significant efforts have been devoted to developing highly efficient PSCs by utilizing a SnO 2 ETL. [28][29][30][31][32][33][34][35][36] Thus far, the certified efficiency of cells with a SnO 2 ETL has reached 23.3%, the highest efficiency for the planar-type PSCs reported to date 37 ; however, based on the Shockley-Queisser theory, the theoretical PCE limit is 30.5%. The main reason for PCE loss is carrier recombination.…”