Tetrahedral amorphous carbon prepared filter cathodic vacuum arc for hole transport layers in perovskite solar cells and quantum dots LEDs

Comparison of NiO x thin film deposited by spin-coating or thermal evaporation for application as a hole transport layer of perovskite solar cells

We compared nickel oxide (NiO_x) deposited by thermal evaporation and that deposited by the spin-coating process, for use in the hole transport layers of inverted planar perovskite solar cells (PSCs). Spin-coating deposition for NiO_x HTL has been widely used, owing to its simplicity, low cost, and high efficiency. However, the spin-coating process has a technical limit to depositing a large-area uniformly. In contrast, thermal evaporation fabrication has a low price and is able to produce uniform and reproducible thin film. Hence, the chemical states, energy band alignment, surface morphologies, and microstructures of NiO_x deposited by spin coating and thermal evaporation were analyzed. The PSC with NiO_x HTL deposited by thermal evaporation showed a higher power conversion efficiency of 16.64% with open circuit voltage 1.07 V, short circuit current density of 20.68 mA cm⁻², and a fill factor of 75.51% compared to that of PSC with spin-coated NiO_x. We confirmed that thermal evaporation can deposit NiO_x to give a better performance as a HTL with higher reproducibility than spin-coating.

We compared nickel oxide (NiO_x) deposited by thermal evaporation and that deposited by the spin-coating process, for use in the hole transport layers of inverted planar perovskite solar cells (PSCs).

Thermally-evaporated C60/Ag/C60 multilayer electrodes for semi-transparent perovskite photovoltaics and thin film heaters

We investigated the characteristics of thermally evaporated fullerene (C60)/Ag/C60 (CAC) multilayer films for use in semi-transparent perovskite solar cells (PSCs) and thin-film heaters (TFHs). The top and bottom C60 layers and Ag interlayer were prepared using multi-source thermal evaporation, and the thickness of the Ag interlayer was investigated in detail for its effects on the resistivity, optical transmittance, and mechanical properties of the CAC electrodes. We used a figure-of-merit analysis to obtain a CAC electrode with a smooth surface morphology that exhibited a sheet resistance of 5.63 Ohm/square and an optical transmittance of 66.13% at a 550 nm wavelength. We conducted mechanical deformation tests to confirm that the thermally evaporated multilayer CAC electrode has a high durability, even after 10,000 times of inner and outer bending, rolling, and twisting due to the flexibility of the amorphous C60 and Ag interlayer. We evaluated the feasibility of using CAC electrodes for semi-transparent PSCs and TFHs. The semi-transparent PSC with 1.08 cm2 active area prepared with a transparent multilayer CAC cathode showed a power conversion efficiency (PCE) of 5.1%. Furthermore, flexible TFHs (2.5 × 2.5 cm2) fabricated on a thermally evaporated CAC electrode show a high saturation temperature of 116.6 C, even at a low input voltage of 4.5 V, due to a very low sheet resistance. Based on the performance of the PSCs and TFHs, we conclude that the thermally evaporated multilayer CAC electrode is promising for use as a transparent conductive electrode (TCE) for semi-transparent PSCs and TFHs, with characteristics comparable to sputtered TCEs.