Charge Carriers Modulate the Bonding of Semiconductor Nanoparticle Dopants As Revealed by Time-Resolved X-ray Spectroscopy.
Asra HassanXiaoyi ZhangXiaohan LiuClare E RowlandAli M JawaidSoma ChattopadhyayAhmet GulecArmen ShamirianXiaobing ZuoRobert F KlieRichard D SchallerPreston T SneePublished in: ACS nano (2017)
Understanding the electronic structure of doped semiconductors is essential to realize advancements in electronics and in the rational design of nanoscale devices. Reported here are the results of time-resolved X-ray absorption studies on copper-doped cadmium sulfide nanoparticles that provide an explicit description of the electronic dynamics of the dopants. The interaction of a dopant ion and an excess charge carrier is unambiguously observed via monitoring the oxidation state. The experimental data combined with DFT calculations demonstrate that dopant bonding to the host matrix is modulated by its interaction with charge carriers. Furthermore, the transient photoluminescence and the kinetics of dopant oxidation reveal the presence of two types of surface-bound ions that create midgap states.
Keyphrases
- quantum dots
- high resolution
- visible light
- density functional theory
- solar cells
- perovskite solar cells
- hydrogen peroxide
- dual energy
- electronic health record
- molecular dynamics
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- genome wide
- metal organic framework
- computed tomography
- single molecule
- big data
- atomic force microscopy
- magnetic resonance imaging
- molecular docking
- case control
- gene expression
- aqueous solution
- single cell
- data analysis
- risk assessment
- machine learning
- electron transfer
- blood brain barrier
- brain injury