Efficient and Stable Carbon-Based Perovskite Solar Cells Enabled by Mixed CuPc:CuSCN Hole Transporting Layer for Indoor Applications

Abstract

Perovskite solar cells (PSCs) are an innovative technology with great potential to offer cost-effective and high-performance devices for converting light into electricity that can be used for both outdoor and indoor applications. In this study, a novel hole-transporting layer (HTL) was created by mixing copper phthalocyanine (CuPc) molecules into a copper­(I) thiocyanate (CuSCN) film and was applied to carbon-based PSCs with cesium/formamidinium (Cs0.17FA0.83Pb­(I0.83Br0.17)3) as a photoabsorber. At the optimum concentration, a high power conversion efficiency (PCE) of 15.01% was achieved under AM1.5G test conditions, and 32.1% PCE was acquired under low-light 1000 lux conditions. It was discovered that the mixed CuPc:CuSCN HTL helps reduce trap density and improve the perovskite/HTL interface as well as the HTL/carbon interface. Moreover, the PSCs based on the mixed CuPc:CuSCN HTL provided better stability over 1 year due to the hydrophobicity of CuPc material. In addition, thermal stability was tested at 85 °C and the devices achieved an average efficiency drop of approximately 50% of the initial PCE value after 1000 h. UV light stability was also examined, and the results revealed that the average efficiency drop of 40% of the initial value for 70 min of exposure was observed. The work presented here represents an important step toward the practical implementation of the PSC as it paves the way for the development of cost-effective, stable, yet high-performance PSCs for both outdoor and indoor applications.

Stabilizing Precursor Solution and Controlling Crystallization Kinetics Simultaneously for High‐Performance Perovskite Solar Cells

“…We also compared the highest PCEs reported so far for PSCs, organic photovoltaics (OPV), dye-sensitized solar cells (DSSCs), a-silicon (a-Si), gallium arsenide (GaAs), copper indium gallium selenium (CIGS), and carbon-based or tin-based single-junction indoor photovoltaic cells in Figure 4g. [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] The 42.43% PCE is the highest value reported so far among all indoor photovoltaic cells. Compared to previously reported perovskite indoor photovoltaic cells (Figure 4h), the higher PCE of the TFFHincorporated cell is mostly attributed to the improved FF.…”

NaCl-Induced PbI2 Passivation Enhancement on Cs0.17FA0.83Pb(I0.83Br0.17)3 Thin Films for Perovskite Solar Cells

“…This contributes to an effective charge extraction and transport process. 48,49 Steady-state photoluminescence (PL) was measured to investigate charge recombination in the perovskite layer. Perovskite films with a 2 mg/mL NaCl additive and without an additive were fabricated on plain glass substrates.…”

“…Interestingly, the optimized device demonstrates a relatively higher V bi value compared to the control device, which correlates with the increased V oc in the device using the NaCl additive. This contributes to an effective charge extraction and transport process. , …”

Efficient and Stable CuSCN-based Perovskite Solar Cells Achieved by Interfacial Engineering with Amidinothiourea

“…Compared with synthetic organic hole-transport materials (HTM), cuprous thiocyanate (CuSCN) is regarded as a cheap but effective inorganic HTM for the fabrication of perovskite solar cells (PSCs), owing to abundant copper reserves on the earth, − high charge mobility, excellent energy level alignment, and satisfactory chemical stability. − So far, CuSCN-based PSCs have attained a certified champion power conversion efficiency (PCE) of 20.4% . Furthermore, compared to organic HTMs, CuSCN is found to protect perovskite layers from oxygen and moisture attack. − All of these advantages promise a bright prospect for CuSCN-based perovskite solar cells. − However, CuSCN has limited application in solution-processed PSCs due to its poor solubility. − The solvents for dissolving CuSCN are only a few short-chain n -alkyl sulfides and diethyl sulfides (DES), but they are likely to destroy perovskite layers simultaneously. − This results in an Ohmic contact degradation between the perovskite and CuSCN layers, which further weakens the power conversion efficiency of PSCs. − …”