Properties of Pulsed-Laser-Deposited CuI and Characteristics of Constructed Dye-Sensitized TiO₂|Dye|CuI Solid-State Photovoltaic Solar Cells

Suppression of Grain Boundary Scattering in Multifunctional p‐Type Transparent γ‐CuI Thin Films due to Interface Tunneling Currents

“…This distinct grain structure and the gaps between the grains result in a high density of grain boundaries in the thin films, respectively. Such a granular structure is often reported for CuI thin films grown with various deposition methods and is also common for CuI thin films used in optoelectronic devices, where grain boundary effects should therefore also be expected. Even epitaxial thin films grown on crystalline substrates, for example, ZnO show (well‐oriented) rotational domains such that grain boundary effects should also be present and can limit the performance of devices especially for lateral transport.…”

“…The first one who fabricated transparent conductive CuI as early as 1907 was Karl Bädeker using a iodization routine for copper thin films, making it the first transparent conductive material discovered. In recent times, there are reports on γ‐CuI thin films grown via reactive sputtering of Cu‐targets, RF‐DC‐sputtering of γ‐CuI targets, thermal evaporation, atomizer techniques, metal–organic chemical vapor deposition, laser‐assisted molecular beam epitaxy, the Bädeker iodization routine, pulsed laser deposition, a solid iodination method, or coating techniques . The highest reported mobility in γ‐CuI thin films is 25 cm 2 V −1 s −1 for thermally evaporated films, most other reports also observe rather high mobilities for p‐type thin films in the range of 10 cm 2 V −1 s −1 in combination with high carrier densities above 10 18 cm −3 .…”

Transparent conductive CuI thin films prepared by pulsed laser deposition

“…Among these techniques, highly transparent and conductive CuI thin films can be obtained, for example, Tanaka et al 7, 10 obtained CuI films with a resistivity of the order of 10 −2 Ω cm and 60–80% transmittance at wavelength of 550–900 nm by rf–dc coupled magnetron sputtering and vacuum evaporation techniques; Tennakone et al 2 deposited CuI films by solvent evaporation, and a minimum sheet resistance of 25 Ω/cm 2 for a film with a thickness of 10 µm was obtained after optimization of iodine doping, sintering time, and temperature. Compared with these reports, Sirimanne et al reported that CuI thin films produced by a PLD technique exhibited a high resistivity of approximately 2 × 10 3 Ω cm 3, 4, 8, 9. In this paper, we investigate the effects of preparation conditions of a PLD technique on the structure and optical–electrical properties of CuI films, and improved optical–electrical properties are obtained.…”

“…Among these phases, α‐phase is a mixed conductor, where the carrier is predominantly Cu 2+ ions; the β‐phase is an ionic conductor; and the γ‐phase (below 350 °C) is a p‐type semiconductor, whose conductivity depends on the presence of iodine in stoichiometric excess 1, 2. In particular, γ‐CuI can be used to construct a fully solid‐state dye‐sensitized photovoltaic cell and as a buffer layer in CuInX 2 (X = S, Se, and Te) ‐based solar cells 3–6, and the utility of this material for these purposes depends on the optical transparency and hole conductivity of CuI.…”

“…Different methods, such as magnetron sputtering 7, pulsed laser deposition (PLD) 3, 4, 8, 9, vacuum evaporation 10, laser‐assisted molecular deposition 11, chemical bath deposition (CBD) 12, successive ionic layer adsorption and reaction (SILAR) 9, 12, 13, and solvent evaporation 2, 9 had been used to prepare CuI thin films. Among these techniques, highly transparent and conductive CuI thin films can be obtained, for example, Tanaka et al 7, 10 obtained CuI films with a resistivity of the order of 10 −2 Ω cm and 60–80% transmittance at wavelength of 550–900 nm by rf–dc coupled magnetron sputtering and vacuum evaporation techniques; Tennakone et al 2 deposited CuI films by solvent evaporation, and a minimum sheet resistance of 25 Ω/cm 2 for a film with a thickness of 10 µm was obtained after optimization of iodine doping, sintering time, and temperature.…”