Compared to their inorganic counterparts, organic semiconductors suffer from relatively low charge carrier mobilities. Therefore, expressions derived for inorganic solar cells to correlate characteristic performance parameters to material properties are prone to fail when applied to organic devices. This is especially true for the classical Shockley-equation commonly used to describe current-voltage (JV)-curves, as it assumes a high electrical conductivity of the charge transporting material. Here, an analytical expression for the JV-curves of organic solar cells is derived based on a previously published analytical model. This expression, bearing a similar functional dependence as the Shockley-equation, delivers a new figure of merit α to express the balance between free charge recombination and extraction in low mobility photoactive materials. This figure of merit is shown to determine critical device parameters such as the apparent series resistance and the fill factor.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4845057 | PMC |
http://dx.doi.org/10.1038/srep24861 | DOI Listing |
Sensors (Basel)
January 2025
Department of Applied Physics and Science Education, Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
The design of optical sensors aims at providing, among other things, the highest precision in the determination of the target measurand. Many sensor systems rely on a spectral transducer to map changes in the measurand into spectral shifts of a resonance peak in the reflection or transmission spectrum, which is measured by a readout device (e.g.
View Article and Find Full Text PDFSensors (Basel)
January 2025
School of Electrical Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China.
In this paper, a new sensor structure is designed, which consists of a metal-insulator-metal (MIM) waveguide and a circular protrusion and a rectangular triangular cavity (CPRTC). The characterization of nanoscale sensors is considered using an approximate numerical method (finite element method). The simulation results show that the sharp asymmetric resonance generated by the interaction between the discrete narrow-band mode and the continuous wideband mode is called Fano resonance.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
As reported during the last five years, SnSe is one of the leading thermoelectric (TE) materials with a very low lattice thermal conductivity. However, its elements are not as heavy as those of classical thermoelectric materials like PbTe or BiTe. Its outstanding TE properties were revealed after repeated purification steps to minimize the amount of oxygen contamination, followed by spark plasma sintering.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Department of Polymer Engineering, Pukyong National University, Busan 48513, Republic of Korea.
Carbon nanotubes (CNTs) have drawn great attention as promising candidates for realizing next-generation printed thermoelectrics (TEs). However, the dispersion instability and resulting poor printability of CNTs have been major issues for their practical processing and device applications. In this work, we investigated the TE characteristics of water-processable carboxymethyl cellulose (CMC) and single-walled CNT (SWCNT) composite.
View Article and Find Full Text PDFMicromachines (Basel)
January 2025
School of Automation and Electrical Engineering, Shenyang Ligong University, Shenyang 110159, China.
In the present study, a novel normally-off vertical GaN MOSFET with an enhanced AlGaN/GaN channel on the sidewall has been proposed using the technology computer-aided design (TCAD) simulation. By using the selective area growth process, the trench structure and the enhanced sidewall channel are formed simultaneously, which is beneficial to enhance the conduction capability compared with the conventional trenched MOSFET. It demonstrates that a proper hole concentration and thickness of the p-GaN layer are key parameters to balance the threshold voltage, on-state resistance, and off-state breakdown voltage, resulting in the highest Baliga's figure of merit value.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!