The model for intrinsic defects in Cu(In,Ga)Se semiconductor layers is still under debate for the full range between CuInSe and CuGaSe. It is commonly agreed by theory and experiment, that there are at least one shallow donor and two shallow acceptors. Spatially resolved photoluminescence on CuGaSe previously revealed a third acceptor. In this study we show with the same method that the photoluminescence peak at 0.94 eV in CuInSe, previously attributed to a third acceptor, is a phonon replica. However another pronounced peak at 0.9 eV is detected on polycrystalline CuInSe samples grown with high copper and selenium excess. Intensity and temperature dependent photoluminescence measurements reveal that this peak originates from a DA-transition from a shallow donor (<8 meV) into a shallow acceptor A3 (135 [Formula: see text] 10) meV. The DA3 transition has three distinct phonon replicas with 28 meV spectral spacing and a Huang Rhys factor of 0.75. Complementary admittance measurements are dominated by one main step with an activation energy of 125 meV which corresponds well with the found A3 defect. The same defect is also observed in Cu(In,Ga)Se samples with low gallium content. For [Ga]/([Ga] + [In])-ratios of up to 0.15 both methods show a concordant increase of the activation energy with increasing gallium content shifting the defect deeper into the bandgap. The indium vacancy [Formula: see text] is discussed as a possible origin of the third acceptor level in CuInSe and [Formula: see text] in Cu(In,Ga)Se.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1088/1361-648X/ab2e24 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Salts of 2-amino-5-iodo-pyridinium.
Acta Crystallogr E Crystallogr Commun
October 2024
Carlson School of Chemistry and Biochemistry, Clark University, 950 Main St., Worcester, MA 01610, USA.
Reaction of 2-amino-5-iodo-pyridine (5IAP) with concentrated HBr at room temperature yielded 2-amino-5-iodo-pyridinium bromide, CHIN ·Br or (5IAPH)Br. The complex formed pale-yellow crystals, which exhibit significant hydrogen bonding between the amino and pyridinium N-H donors and bromide ion acceptors. Halogen bonding is also observed.
View Article and Find Full Text PDFCF-Functionalized Side Chains in Nonfullerene Acceptors Promote Electrostatic Interactions for Highly Efficient Organic Solar Cells.
J Am Chem Soc
December 2024
Department of Chemistry, the Materials Research Center, Trienens Institute for Sustainability and Energy Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
The advent of next-generation nonfullerene acceptors (NFAs) has propelled major advances in organic solar cells (OSCs). Here we report an NFA design incorporating CF-terminated side chains having varying -(CH)-CF linker lengths ( = 1, 2, and 3) which introduce new intermolecular interactions, hence strong modulation of the photovoltaic response. We report a systematic comparison and contrast characterization of this NFA series with a comprehensive set of chemical/physical techniques versus the heavily studied third-generation NFA, Y6, revealing distinctive and beneficial properties of this new NFA series.
View Article and Find Full Text PDFSynergistic Multimodal Energy Dissipation Enhances Certified Efficiency of Flexible Organic Photovoltaics beyond 19.
Adv Mater
December 2024
College of Chemistry and Chemical Engineering/ Film Energy Chemistry for Jiangxi Provincial Key Laboratory (FEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
All-polymer organic solar cells (OSCs) have shown unparalleled application potential in the field of flexible wearable electronics in recent years due to the excellent mechanical and photovoltaic properties. However, the small molecule acceptors after polymerization in still retain some mechanical and aggregation properties of the small molecule, falling short of the ductility requirements for flexible devices. Here, based on the multimodal energy dissipation theory, the mechanical and photovoltaic properties of flexible devices are co-enhanced by adding the thermoplastic elastomer material (polyurethane, PU) to the PM6:PBQx-TF:PY-IT-based active layer films.
View Article and Find Full Text PDFCRISPR-Cas9-Mediated Correction of Pathogenic Variants in iPSCs from Patients with Tuberous Sclerosis Complex Type 2.
CRISPR J
December 2024
The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by mutations in either the or genes. Though TSC causes the formation of nonmalignant tumors throughout multiple organs, the most frequent causes of mortality and morbidity are due to neurological complications. In two-thirds of cases, TSC occurs sporadically and pathogenic variants are approximately three times more prevalent than pathogenic variants.
View Article and Find Full Text PDFCooperative Catalysis in Stereoselective - and -Glycosylations with Glycosyl Trichloroacetimidates Mediated by Singly Protonated Phenanthrolinium Salt and Trichloroacetamide.
J Am Chem Soc
December 2024
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
The development of small-molecule catalysts that can effectively activate both reacting partners simultaneously represents a pivotal pursuit in advancing the field of stereoselective glycosylation reactions. We report herein the development of the singly protonated form of readily available phenanthroline as an effective cooperative catalyst that facilitates the coupling of a wide variety of aliphatic alcohols, phenols, and aromatic amines with α-glycosyl trichloroacetimidate donors. The glycosylation reaction likely proceeds via an S2-like mechanism, generating β-selective glycoside products.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!