Essays about: "exciton binding energy"

Showing result 1 - 5 of 6 essays containing the words exciton binding energy.

  1. 1. Photophysics of the polymer acceptor PF5-Y5 in organic photovoltaics : A first principles theory based study

    University essay from Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)

    Author : Anton Almén; [2022]
    Keywords : PF5-Y5; Non-fullerene-acceptor; NFA; polymer; fundamental; optical; gap; oxidation; reduction; exciton; binding; energy; oligomer; length; PF5-Y5; Non-fullerene-acceptor; NFA; polymer; fundamentalt; optiskt; gap; oxidation; reduktion; exciton; binding; energi; oligomerlängd;

    Abstract : Non-fullerene Acceptors (NFAs) have gathered a great deal of interest for use inorganic photovoltaics (OPVs) due to recent breakthroughs in their power conversion efficiency and other advantages they offer over their Fullerene-based counterparts. In this work, a new promising non-fullerene polymer acceptor, PF5-Y5, have been studied using density functional theory and time-dependent density functional theory; and the effects that oligomer length, geometry relaxation and exchange-correlation interaction has on the exciton binding energies (the difference between optical and fundamental energy gaps) have been investigated. READ MORE

  2. 2. Charge transfer states at polymer solar cell interfaces : Insights from atomic-scale modeling

    University essay from Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)

    Author : Rickard Svensson; [2022]
    Keywords : organic solar cells; OSC; polymer; interface; charge transfer; non-fullerene acceptor; PYT; PBDB-T; DFT; TD-DFT; conformation; alkyl groups; methylation; HOMO; LUMO; FMO; NTO; UV-Vis; DOS; exciton; exciton binding energy; dipole moment; open-circuit voltage; organiska solceller; OSC; polymer; gränssnitt; laddningsöverföring; icke-fullerenacceptor; PYT; PBDB-T; DFT; TD-DFT; konformation; alkylgrupper; metylering; HOMO; LUMO; FMO; NTO; UV-Vis; DOS; exciton; excitonbindningsenergi; dipolmoment; tomgångsspänning;

    Abstract : Organic solar cells (OSCs) based on non-fullerene acceptors (NFAs) have attracted a great deal of attention in recent years due to their rapidly increasing efficiency and enormous potential. In this work, the optical and electronic properties of systems containing the very promising non-fullerene acceptor PYT have been thoroughly studied with the use of the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). READ MORE

  3. 3. Evaluation of Zinc Oxide Nano-Microtetrapods for Biomolecule Sensing Applications

    University essay from KTH/Funktionella material, FNM

    Author : Wei Zhao; [2015]
    Keywords : zinc oxide tetrapods; nano-microstructure; glucose oxidase; glucose sensor;

    Abstract : Zinc oxide (ZnO) is a well-known II-VI semiconductor material that has gained renewed interest in the past decade due to the developments of growth technologies and the availability of high-quality ZnO bulk single crystals. Owing to a wide direct band gap (3. READ MORE

  4. 4. Time-resolved study of charge photo-generation in polymer-based solar cells with low driving force

    University essay from Lunds universitet/Fysiska institutionen

    Author : Paulius Baronas; [2014]
    Keywords : Organic polymer solar cells; BHJ solar cells; Charge photo-generation; Driving force; Time resolved photoluminescence; CT states; Physics and Astronomy;

    Abstract : Organic polymer-based solar cells recently attracted much attention as an efficient and inexpensive light-to-electricity conversion solution. However, the mechanism behind charge generation processes in organic materials is still not fully understood due to complex nature of carbon-based compounds. READ MORE

  5. 5. Investigation of ZnO nanorods for UV detection

    University essay from KTH/Skolan för informations- och kommunikationsteknik (ICT)

    Author : David Boban Rihtnesberg; [2011]
    Keywords : ;

    Abstract : In recent years, there has been increasing interest in ZnO semiconductors for optoelectronic application in the UV wavelength region due to its large exciton binding energy of 60 meV and wide bandgap energy of 3,37 eV at room temperature. One-dimensional ZnO nanostructures such as nanorods or nanowires have been considered as promising candidates for UV sensing and detecting applications owing to its high surface to volume ratio. READ MORE