Thin nanocrystalline semiconductor films as selective chemical sensors for ammonia, acetone and other donors

Studied are the films of variously doped polycrystalline n-semiconductors (ZnO, SnO2) as selective sensitive elements (SE) of chemical sensors for various gases and vapours (ammonia, acetone, propane, ethanol, hexane, solvent, turpentine etc.) in artificial air. It has been revealed that their conductivity changes under temperature modulation makes possible data processing which identifies the impurities above. This processing is based on nonlinear regression estimation of so called principal parameters which set is unique for every concentration of every of the gases/vapours.

Use of Natural Sensitizers of TiO2-Nanocrystalline Semiconductor for the Construction of DSSC

ABSTRACTThis work describes the electrical behavior of dye sensitized solar cells manufactured with TiO2-nanocrystalline semiconductor sensitized with diverse natural tints. A number of natural sensitizers have been tested, including red fruits as blackberries, hibiscus and beet in order to comprehend the relationship between anthocyanin and electron transfer and green vegetables as spinach and grass, as well as for known the relationship between chlorophyll and electron transfer. The nanocrystalline semiconductor was characterized by XRD, FTIR and SEM. The bands observed at 931, 667 and 514 cmˉ1 in the FTIR spectrum confirmed the presence of Ti-O-Ti bonds. From DRX analysis it is confirmed the presence of TiO2 in its anatase form. This study confirms the great potential of the use of organic dyes for sensitized the TiO2-semiconductor. Principally, in blackberries it has reached values around 300 mV owing to high concentrations of purple pigment due to the molecule called anthocyanin and the anchoring properties of the anthocyanin with the TiO2-nanocrystalline semiconductor.

Deposition Voltage Research of CdSe Quantum Dots Sensitized TiO2 Solar Cell

TiO2nanocrystalline semiconductor film was made on the titanium (Ti) substrate by hydrothermal method,and then prepared the CdSe quantum dot layer on the face of the TiO2nanocrystalline semiconductor film by electrochemical deposition method. We studied the affect of deposition voltage of the CdSe quantum dots’ growth, finding that when the deposition voltage was-1.3V,CdSe quantum dots grown best.However, In terms of CdSe/TiO2as the light-anode,using electricity chemistry workstation to test,We gain a solar cell with Short circuit current density of 1.45×10-3A·cm-2and the open circuit voltage of 0.24 V.