SnO2 modified mesoporous ZrO2 as efficient electron-transport layer for carbon-electrode based, low-temperature mesoscopic perovskite solar cells

Abstract

SnO2 modified mesoporous ZrO2 is used to replace the mesoporous TiO2 layer and serves as a kind of mesoporous electron-transport layer during the low-temperature fabrication of mesoscopic perovskite solar cells that are based on carbon electrode. X-ray/ultraviolet photoelectron spectroscopy studies and electrical test observe that SnO2 modification brought down the work function while increasing the conductivity of the mesoporous ZrO2. Transient photovoltage/photocurrent decay curves, impedance spectroscopy, and photoluminescence mapping show that after the bottom layer of ZrO2 is modified by SnO2, the charge extraction process is accelerated while recombination is retarded. This modification helps to increase the power conversion efficiency from 4.70 (±0.85)% to 10.15 (±0.35)%, along with the optimized efficiency at 13.37% (AM1.5G, 100 mW/cm2) for the low-temperature devices. In addition, the effects of modification layers of SnO2 on the power conversion properties are carefully studied. This study shows that SnO2 modified mesoporous ZrO2 could serve as an efficient electron-transport layer for the low-temperature mesoscopic devices.

Improved Interfacial Contact Between “Perovskite/Electron‐Transport Layer” by Hydrophilic Molecule to Achieve Efficiency >14%, Carbon Electrode‐Based, Hole‐Conductor‐Free, Low‐Temperature Mesoscopic Perovskite Solar Cells

“…At last, storage stability is tested; the results are shown in Figure S6, Supporting Information. Similar to that observed before, [16,18] good storage stability is observed for the low-temperature meso-CPSCs.…”

“…PCEs are peaked from the published literatures for both low-and high-temperature devices. [16,18,[51][52][53][54][55][56][57][58][59] The red arrows show the PCE gap (%). and retard recombination, and then upgrade device efficiency of the low-temperature meso-CPSCs.…”

“…Materials Synthesis: SnO 2 quantum dots (SnO 2 QDs) colloid (0.15 M) was prepared like that described before. [18] Carbon paste was prepared by ball-milling graphite (2 g) and carbon black (0.25 g) in ethanol for 24 h. After that, 5 mL of ZrO 2 colloid was mixed with the ball-milled carbon paste so as to act as the gel-binders. [18] For OAI modification on CE, 140 mg OAI was added to the carbon paste.…”

“…[16] Device Fabrication: The conductive glass substrate FTO was treated using the same treatment as in previous experiments. [18] For device fabrication, SnO 2 QDs colloid was spin-coated (3000 rpm, 60 s) on FTO. The HPβCD (0, 6, 12, 24 mg mL À1 )-doped TiO 2 suspension was spin-coated (2000 rpm, 30 s) on top of the SnO 2 dense layer.…”

Octylammonium Iodide Induced In‐situ Healing at “perovskite/Carbon” Interface to Achieve 85% RH‐moisture Stable, Hole‐Conductor‐Free Perovskite Solar Cells with Power Conversion Efficiency >19%

“…We have further examined the OAI induced in‐situ healing effect by performing “penetration‐reaction test”. As is shown in Figure a–c, a thin layer of mesoporous ZrO 2 (meso‐ZrO 2 ) is coated on 3D PVSK layer (ZrO 2 is chosen since it is insulating according to studies in meso CPSCs [ 50 ] ). Then carbon‐electrode is deposited on top.…”