Core–Shell ZnO@SnO₂ Nanoparticles for Efficient Inorganic Perovskite Solar Cells

Abstract

The ideal charge transport materials should exhibit a proper energy level, high carrier mobility, sufficient conductivity, and excellent charge extraction ability. Here, a novel electron transport material was designed and synthesized by using a simple and facile solvothermal method, which is composed of the core−shell ZnO@SnO 2 nanoparticles. Thanks to the good match between the energy level of the SnO 2 shell and the high electron mobility of the core ZnO nanoparticles, the PCE of inorganic perovskite solar cells has reached 14.35% (J SC : 16.45 mA cm −2 , V OC : 1.11 V, FF: 79%), acting core−shell ZnO@SnO 2 nanoparticles as the electron transfer layer. The core−shell ZnO@SnO 2 nanoparticles size is 8.1 nm with the SnO 2 shell thickness of 3.4 nm, and the electron mobility is seven times more than SnO 2 nanoparticles. Meanwhile, the uniform core−shell ZnO@SnO 2 nanoparticles is extremely favorable to the growth of inorganic perovskite films. These preliminary results strongly suggest the great potential of this novel electron transfer material in high-efficiency perovskite solar cells.

Inorganic Halide Perovskite Solar Cells: Progress and Challenges

“…[ 110 ] Recently, Li et al used a solvothermal method to synthesize the core–shell ZnO@SnO 2 nanoparticles, which showed superior electron mobility to the pristine SnO 2 nanoparticles and better matched energy levels with CsPbI 2 Br perovskite. [ 111 ] The optimized CsPbI 2 Br PSCs based on the ZnO@SnO 2 ETL achieved a high PCE of 14.35% along with a current density ( J SC ) of 16.45 mA cm −2 , a V OC of 1.11 V, and a fill factor (FF) of 79%. Zeng et al replaced the Spiro‐OMeTAD layer with a thin poly(3‐hexylthiophene) (P3HT) layer, which with low energy disorder can passivate the defect states on the surface of CsPbI 2 Br film, resulting in a high V OC of 1.32 V and a low E loss of 0.5 eV (Figure 13b–e).…”

Ambient Stable and Efficient Monolithic Tandem Perovskite/PbS Quantum Dots Solar Cells via Surface Passivation and Light Management Strategies

“…We find that the NWsbased sample shows higher absorption due to better light trapping properties of NWs and stronger quenching effect due to larger surface area as compared to the planar sample. [5] To study the influence of the SnO 2 interface layer on the device performance, PSCs based on NWs and NWs/SnO 2 ETLs were fabricated. Figure 3a 3 mA cm −2 , a fill factor (FF) of 67%, and a decent PCE of 15%.…”

Organic Ligands Armored ZnO Enhances Efficiency and Stability of CsPbI2Br Perovskite Solar Cells

“…Although incorporating inorganic cations (potassium, rubidium, Cs + ) into the organic/inorganic hybrid perovskites or pretreating ZnO materials can stabilize perovskite to some extent, the unsatisfied stability and complicated fabrication processes are not favorable during commercialization. [25][26][27][28] After substituting all organic cations with Cs + to form inorganic perovskite, organic components are absent to allow ZnO to degrade. Cao and co-workers [29] applied a SnO 2 /ZnO bilayer ETL to promote desirable cascade energy levels with CsPbI 2 Br, devices of which exhibit improved stability and open-circuit voltage (V OC ) (1.06 to 1.23 V), demonstrating that ZnO is a promising ETM for inorganic PSCs.…”