Mechanism of charge transport in ligand-capped crystalline CdTe nanoparticles according to surface photovoltaic and photoacoustic results

作者：Li Kuiying^*; Zhang Hao; Yang Weiyong; Wei Sailing; Wang Dayang

来源：Materials Chemistry and Physics, 2010, 123(1): 98-103.

DOI：10.1016/j.matchemphys.2010.03.066

• Semiconductors
• Chemical synthesis
• Photoelectron spectroscopy
• Surface properties

By combining surface photovoltaic and photoacoustic techniques, we probed the photogenerated charge transport channels of 3-mercaptopropionic acid (MPA)- and 2-mercaptoethylamine (MA)-capped crystalline CdTe nanoparticles on illumination with UV-near IR light. The results experimentally confirmed the presence of a CdS shell outside the CdTe core that formed through the self-assembly and decomposition of mercapto ligands during CdTe preparation. The data revealed that the CdS layer was partly responsible for the deexcitation behavior of the photogenerated carriers, which is related to the quantum tunnel effect. Experiments demonstrated that two quantum wells were located at wavelengths of 440 and 500 nm in buried interfacial space-charge regions, whereas the formation of a ligand layer obstructed charge transfer transitions of the core CdTe nanoparticles to a certain extent.

• 出版日期2010-9-1
• 单位吉林大学; 燕山大学