광전 변환 소자 응용을 위한 다양한 무기 박막의 제조

Abstract

Tubular end-capped electrodeposited CdSe nanofibers reports for the first time tubular end-capped nanofibers of CdSe on ITO substrates developed using electrodeposition chemistry. We investigated the surface morphology and extended further to examine photoelectrochemical performance. As-formed ITO/CdSe/polysulphide/Pt photoelectrochemical cell showed 2 % photo-conversion efficiency under 80 mW/cm2 light intensity, when used in the photoelectrochemical-type cells CdSe nanofiber based photoelectrochemical cells has studied the influence of annealing temperatures on the crystal structure, surface morphology, optical and photoelectrochemical (PEC) properties of CdSe nanofiber film electrodes synthesized by electrodeposition technique. The crystal structure and surface morphology of CdSe film electrodes were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. The optical absorption of as-synthesized and annealed CdSe films on tin-doped indium oxide (ITO) substrates were measured by UV-Vis spectrophotometer. As-synthesized amorphous /nanocrystalline CdSe film electrodes were changed to crystalline after annealing at 473 K for 1 h, where the improved photoelectrochemical performance conversion efficiency of 2.01 % was obtained. Upright-standing ZnO nano-sheets growth using wet chemistry introduces room temperature solution processing for making cross-linked upright-standing ZnO nano-sheets growth of ~2-5 um in length and ~100-150 nm in width. These nano-sheets are characterized for structural and surface morphological analyses. Energy dispersive X-ray spectrum is used to chemical analysis. Confirmation of well defined cross-linked and distinct ZnO nano-sheets of quoted dimensions is carried out using a scanning electron microscopy. Porous nature of nano-sheets with fine edge boundaries is noted from low resolution transmission electron microscopy. Chemical bath deposition of CdS quantum dots on vertically aligned ZnO nanorods for Quantum dots-sensitized solar cells introduces that formation of CdS quantum dots (Q dots) on the vertically aligned ZnO nanorods electrode was carried out by chemical bath deposition. The diameter and thickness of ZnO nanorods was ~100-150 nm and ~1.6 um, respectively, and CdS Q dots on ZnO nanorods have a diameter of smaller than 15 nm. In application of the Q dots-sensitized solar cells, composite film exhibited a power conversion efficiency of 0.54 % under the air mass 1.5 condition (80 mW/cm2), and incident-photon-to-current conversion efficiency showed 18.6 %. Reduced recombination and photodegradation processes of photoelectrochemical cell-Based CdSe nanofibers in the presence of PEDOT:PSS layers reports the use of poly(3,4-ethylene dioxy thiophen):poly(styrene sulfonate) (PEDOT: PSS) as a protective layer to reduce the photodegradation and recombination processes of CdSe nanofiber films. Due to reduced photodegradation and recombination processes of photoelectrochemical cell-based CdSe nanofiber films, the power conversion efficiency of CdSe nanofibers films was 1.81 % in the presence of PEDOT:PSS layers under the air mass 1.5 condition (80 mW/cm2), which is an 82.8 % increase compared to films without PEDOT:PSS layers. Furthermore, the CdSe film was highly stable under illumination in the presence of PEDOT:PSS layers. Polymer-sensitized photoelectrochemical solar cells based on water-soluble polyacetylene and ß-In2S3 nanorods presents a method for preparing polymer-sensitized photo electrochemical solar cells (PECs) using water-soluble acetylene polymer photosensitizers and ß-In2S3 nanorods. Since water-soluble acetylene polymers are hydrophilic, they were able to overcome the problems associated with the adhesion of hydrophobic polymers and were well matched with the hydrophilic ß-In2S3 surface. The polymer layers were easily prepared by dipping the ß-In2S3 nanorods films in an aqueous polymer solution, and the resulting polymer-sensitized PECs showed a power conversion efficiency of 1.63% under the air mass 1.5 conditions (I = 80 mW/cm2). Fabrication of high-density single-walled carbon nanotube three-dimensional networks on Si pillar structures and their Photovoltaic application suggests an advanced three-dimensional (3D) electrode structure which can be used for future electronics as nano-electrode having a large active surface area. High-density single-walled carbon nanotube (SWNT) 3D networks (-3DNs) were uniformly synthesized over a micro-sized Si pillar structure by thermal chemical vapor deposition. The SWNT-3DNs had wide diameter distributions corresponding to various electrical properties and were connected to each other by bundling in 3D space. A sandwich-type photoelectrochemical cell was fabricated by coating the SWNT-3DNs with a CdSe quantum dot (-QDs). The CdSe-QDs/SWNT-3DNs/Si pillar solar-cells showed fast photocurrent generation as well as good stability and reliability of photocurrent. Three dimensional CdSe/single-walled carbon nanotubes solar cell with reverse field-enhancement effects introduces the field enhancement phenomenon of SWNTs is utilized to design 3-dimensional (D) CdSe solar cell showing improved performance. In this, fibrous CdSe nanowires were grown onto the SWNT/ITO surface by electrodeposition, which formed a 3-D solar cell system. The photovoltaic performance study of 3-D CdSe/SWNT/ITO solar cell showed 3.34% conversion efficiency under AM 1.5 condition (I = 100 mW/cm2), which is 50 % significantly higher than that without SWNTs layer. The observed improvement in cell performance is attributed to the reverse field enhancement effects of the SWNTs. Interestingly, the reverse field enhancement factor (β value) of CdSe/SWNTs/ITO is found to increase by 380% with SWNTs layer, wherein texturized Si is used as cathode.