Efficient Planar Perovskite Solar Cells with Reduced Hysteresis and Enhanced Open Circuit Voltage by Using PW₁₂–TiO₂ as Electron Transport Layer

Abstract

An electron transport layer is essential for effective operation of planar perovskite solar cells. In this Article, PW12-TiO2 composite was used as the electron transport layer for the planar perovskite solar cell in the device structure of fluorine-doped tin oxide (FTO)-glass/PW12-TiO2/perovskite/spiro-OMeTAD/Au. A proper downward shift of the conduction band minimum (CBM) enhanced electron extraction from the perovskite layer to the PW12-TiO2 composite layer. Consequently, the common hysteresis effect in TiO2-based planar perovskite solar cells was significantly reduced and the open circuit voltage was greatly increased to about 1.1 V. Perovskite solar cells using the PW12-TiO2 compact layer showed an efficiency of 15.45%. This work can contribute to the studies on the electron transport layer and interface engineering for the further development of perovskite solar cells.

It Takes Two to Tango—Double-Layer Selective Contacts in Perovskite Solar Cells for Improved Device Performance and Reduced Hysteresis

“…This is in line with numerous other reports focusing on the optimization of the charge selective material interfacing the perovskite. 21,23,35 Going beyond these findings, in our study we further show that an additional interlayer not in direct contact to the perovskite absorber can have major beneficial effects. By depositing metal oxides between the ITO electrode and a fullerene electron selective contact, we successfully reduce hysteresis effects and strongly improve the power output by ca.…”

“…17,18 It was shown, that highest efficiencies and negligible hysteresis can be achieved in planar n-i-p devices by optimizing the n-type contact. [21][22][23] The reported poor charge extraction properties of TiO2 19 possibly make this material less suitable for planar as compared to mesoscopic solar cells because of the reduced contact area to the absorber. A promising alternative is SnO2 due to its wide band gap and high electron mobilities.…”

Anomalous Charge‐Extraction Behavior for Graphene‐Oxide (GO) and Reduced Graphene‐Oxide (rGO) Films as Efficient p‐Contact Layers for High‐Performance Perovskite Solar Cells

“…[29] The reason for the occurrence of hysteresis in PSC is unclear. [29] The reason for the occurrence of hysteresis in PSC is unclear.…”

SiW12–TiO2 Mesoporous Layer for Enhanced Electron‐Extraction Efficiency and Conductivity in Perovskite Solar Cells

“…In addition, from the thermogravi-metrica nalysis (TGA) and differential thermal analysis (DTA) spectra shown in Figure S1a, the weight lose below almost 500 8Cc an be mainly attributed to the dehydration of SiW 12 , confirming that SiW 12 can maintain the Keggins tructure at the sinteringt emperature of SiW 12 -TiO 2 composites film. [26] In addition, the XPS surveys pectrum andt he other element spectra (Si, W, and O) of SiW 12 -TiO 2 composites are shown in Figure S2. [29,30] The (101) anatase peak of SiW 12 -TiO 2 slightly shifts toward higher 2 q angles than those of pristine TiO 2 (Figure 2b), whichc an be attributed to the insertion of smaller ionic radius W 6 + (60 < Ti 4 + ,6 1)i nto the TiO 2 lattice according to the Scherrer equation:2 d sin q = l (d is the crystalline plane space, q is the diffraction angle of the peak, l is the Xray wavelength).…”

“…Accordingly,m any efforts have already been devoted to modifying and manipulatingp ristine TiO 2 by doping with metal or nonmetal (such as Mg, Al, and Nd), regulating the morphology and crystallinity of TiO 2 (such as nanorods, nanotubes, or rutile phase) and interface engineering of TiO 2 film [bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) or PCBM treatment]. [26] In this work, we fabricatedS iW 12 -TiO 2 composite mesoporous films to be used as ETL in PSCs by af acile one-step spincoating deposition method. [20] POMs have therefore been extensively investigatedi np hotovoltaic fields.…”