TY - JOUR
AB - PbS (lead sulfide) colloidal quantum dots consist of crystallites with diameters in the nanometer range with organic molecules on their surfaces, partly with additional metal complexes as ligands. These surface molecules are responsible for solubility and prevent aggregation, but the interface between semiconductor quantum dots and ligands also influences the electronic structure. PbS quantum dots are especially interesting for optoelectronic applications and spectroscopic techniques, including photoluminescence, photodiodes and solar cells. Here we concentrate on the latter, giving an overview of the optical properties of solar cells prepared with PbS colloidal quantum dots, produced by different methods and combined with diverse other materials, to reach high efficiencies and fill factors.
AU - Blachowicz, Tomasz
AU - Ehrmann, Andrea
ID - 645
IS - 5
JF - Applied Sciences
KW - colloidal PbS quantum dots
KW - quantum dot solar cells
KW - semiconductor
KW - heterojunction
KW - ligand
KW - open-circuit voltage
KW - short-circuit current
KW - power conversion efficiency
KW - fill factor
SN - 2076-3417
TI - Recent Developments of Solar Cells from PbS Colloidal Quantum Dots
VL - 10
ER -
TY - JOUR
AB - Especially for the potential use as sensors, but also in all other applications in which an interaction with the environment occurs, nanofibrous materials are advantageous due to their large specific surface area. An interesting material for electrospinning is the semiconductor zinc oxide (ZnO) which is often used in photoelectric or sensory applications. Nanofibers containing ZnO can be produced, for example, by electrospinning polyvinylpyrrolidone/zinc nitrate from a dimethylformamide/ethanol solution, followed by calcination to remove the organic phase. Alternatively, the polymer/semiconductor blended nanofibers can be used which are often less brittle, but on the other hand offer less contact between ZnO and the environment. Finally, decorating a nanofiber mat with ZnO offers another possibility to prepare nanofibers with ZnO surface. Possible applications of electrospun ZnO nanofibers or nanofiber mats include gas sensing, microwave absorption, photocatalytic degradation or enhancement of supercapacitor electrodes. This short review gives an overview of the most recent electrospinning and after-treatment techniques to create pure and blended ZnO nanofibers and presents the broad variety of possible applications of this well-known semiconductor with some still surprising properties.
AU - Blachowicz, Tomasz
AU - Ehrmann, Andrea
ID - 637
JF - Journal of Engineered Fibers and Fabrics
KW - Electrospinning
KW - ZnO
KW - nanofibers
KW - semiconductor
KW - supercapacitor
KW - nanorods
KW - nanosheets
SN - 1558-9250
TI - Recent developments in electrospun ZnO nanofibers: A short review
VL - 15
ER -
TY - JOUR
AB - Developing dye-sensitized solar cells (DSSCs) further is of utmost importance in a time of increasing energy consumption and the necessity to change to renewable energy sources. Opposite to silicon-based solar cells, DSSCs can be produced from low-cost, non-toxic materials. In addition, they can be applied on flexible substrates, enabling even utilization on textile architecture. On the other hand, reaching efficiencies in a similar order of magnitude as with silicon-based solar cells is only possible by highly pure and toxic materials. This is why optimization of DSSCs with non-toxic and affordable materials is of high interest. Here we report on the possibility to increase the TiO2 layer performance by adding a nonionic surfactant, focusing on a non-toxic electrolyte and a natural dye. Our results show that coating the semiconducting layer from a solvent including a surfactant increases the efficiency of the DSSC. To enable comparison with results of other groups which are often reported for very small active areas, we compare three different areas between 0.25 cm² and 6.0 cm² and show that the efficiencies are more than doubled for the smallest active area in comparison to the largest one. This underlines the necessity to perform more research on large-area DSSCs, e.g. by combining several smaller cells, aiming at possible applications on tents or other large textile areas.
AU - Udomrungkhajornchai, Suphawit
AU - Junger, Irén Juhász
AU - Ehrmann, Andrea
ID - 622
JF - Optik
KW - Dye-sensitized solar cells (DSSCs)
KW - Semiconductor
KW - TiO2
KW - Nonionic surfactant
KW - Triton X-100
KW - Natural dye
KW - Anthocyanin
KW - Active area
SN - 0030-4026
TI - Optimization of the TiO2 layer in DSSCs by a nonionic surfactant
VL - 203
ER -