Optical and electrical properties of complex semiconducting alloys like Cu(In,Ga)Se2 (CIGS) are strongly influenced by the reaction pathways occurring during their deposition process. This makes it desirable to observe and control these properties in real-time during the deposition. Here we show for the first time the evolution of the band gap and the sub-band-gap defect absorption of CIGS thin...

Ultrasensitive room temperature real-time NO₂ sensors are highly desirable due to potential threats on environmental security and personal respiratory. Traditional NO₂ gas sensors with highly operated temperatures (200-600 °C) and limited reversibility are mainly constructed from semiconducting oxide-deposited ceramic tubes or inter-finger probes. Herein, we report the functionalized graphene n...

In organic field-effect transistors (OFETs) the electrical characteristics of polymeric semiconducting materials suffer from the presence of structural/morphological defects and grain boundaries as well as amorphous domains within the film, hindering an efficient transport of charges. To improve the percolation of charges we blend a regioregular poly(3-hexylthiophene) (P3HT) with newly designed...

Direct conversion from heat to electricity is one of the important technologies for a sustainable society since large quantities of energy are wasted as heat. We report the development of a single-walled carbon nanotube (SWNT)-based high conversion efficiency, air-stable and flexible thermoelectric material. We prepared cobaltocene-encapsulated SWNTs (denoted CoCp2@SWNTs) and revealed that the ...

When titanium dioxide (TiO2) is exposed to nearultraviolet light, it exhibits strong bactericidal activity. Anatase phase of TiO2 film was prepared by anodizing pure titanium coupons (substrate). Atomic force microscopy (AFM) technique was used to image the transformation of titanium surface to TiO2 surface on anodization. We observed wide distribution of TiO2 particles ranging from submicron t...

Organic-inorganic hybrid perovskite solar cells are considered as one of the most promising next-generation solar cells due to their advantages of low-cost precursors, high power conversion efficiency (PCE) and easy of processing. In the past few years, the PCEs have climbed from a few to over 20% for perovskite solar cells. Recent developments demonstrate that perovskite exhibits ambipolar sem...

Semiconducting thin films were grown on quartz substrates and crystalline silicon wafers, using dilithium phthalocyanine and the organic ligands 2,6-dihydroxyanthraquinone and 2,6-diaminoanthraquinone as the starting compounds. The films, thus obtained, were characterized by Fourier Transform infrared (FTIR), fast atomic bombardment (FAB+) mass and ultraviolet-visible (UV-Vis) spectroscopies. T...

Joglekar, Chinmay S. M.S.Ch.E., Purdue University, May 2014. CZTSSe Thin Film Solar Cells: Surface Treatments. Major Professor: Rakesh Agrawal. Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 μm thickness are sufficient for the fabrication of so...

In recent years, tetrathiafulvalene (TTF) and its derivatives have been used as semiconducting materials for organic field-effect transistors (OFETs). In this review, we summarize the recent progress in the field of TTF-based OFETs. We introduce the structure and operation of OFETs, and focus on TTF derivatives used in OFETs. TTF derivatives used in OFETs can be divided into three parts by the ...