Enhanced performance of organic photovoltaics by TiO2-interlayer with precisely controlled thickness between ZnO electron collecting and active layers

Development of Inverted Organic Photovoltaics with Anion doped ZnO as an Electron Transporting Layer

“…Another peak in PL spectra shown in the region between 450 nm and 700 nm is giving information about surface defect such as oxygen vacancy and/or point defects of ZnO thin film [22,25,26,30,31]. It is already well known that surface oxygen vacancy of metal oxide film is quite important for the high electrical conductivity of the film.…”

“…Another optical characteristic like photoluminescence (PL) spectroscopy has been widely used to determine the optical band structure, and also PL spectra in the high wavelength represents the status of the surface structure kinds of surface defects of ZnO thin film [22,25,26,30,31]. In conventional PL spectra of ZnO thin film, one can detect two major peaks, one is strong emission peaks in the UV region of 380 nm 400 nm which is related to the property of optical band gap.…”

“…These anion elements can substitute the oxygen atoms in ZnO lattice [20,24,28]. Generally, the oxygen atoms as vacancies can act as an electron-hole recombination sites in I-OPVs [10,30,31], and results in decrease the performance of I-OPV. Among the various methods to reducing the recombination sites of ZnO ETL, anion doping can be one of the ideal concepts, because the atonic radius of group VII anion is almost similar to the oxygen atom as well as their excess electrons can help to achieving the high mobility [23,26] and conductivity [21,24,26] while maintaining high optical transparency [20,21,23,27], compared to group III cation metallic elements.…”

“…The inverted organic photovoltaics (I-OPVs) are using organic polymer materials as photoactive layer, which are cost-effective, portable, and applicable to the flexible substrates [2][3][4][5][6][7][8]. Generally, in I-OPVs, ntype materials such as zinc oxide (ZnO) [9,30,31], titanium dioxide (TiO 2 ) [10,30], and cesium carbonate (Cs 2 CO 3 ) [11,12] have been widely used as hole blocking layer (HBL) [1,13] and electron transporting layer (ETL) [4,[9][10][11][12][13][14]. Among them, ZnO is an intrinsic n-type semiconductor, which has high optical transparency, wide band gap energy (3.2 eV), large exciton binding energy (60 meV), high electron mobility, and conductivity.…”

A Novel of Buton Asphalt and Methylene Blue as Dye-Sensitized Solar Cell using TiO2/Ti Nanotubes Electrode

“…The principle of solar energy by converting sunlight into electrical energy, one of them is DyeSensitized Solar Cell (DSSC) [9]. DSSC is a solar cell based on the semiconductor sensitivity using dye as a sensitizer [10].…”