کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5421774 1507889 2015 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chemically-specific time-resolved surface photovoltage spectroscopy: Carrier dynamics at the interface of quantum dots attached to a metal oxide
ترجمه فارسی عنوان
طیف سنجی سطح فتوولتائیک سطح حل شده با زمان شیمیایی: دینامیک حامل در رابط نقاط کوانتومی متصل به اکسید فلزی
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
چکیده انگلیسی


- Time-resolved surface photovoltage spectroscopy measures carrier dynamics in ZnO.
- A new experimental technique at SOLEIL combines fast XPS with a modulated CW laser.
- Quantum dots are chemically linked to ZnO, a model for next-generation solar cells.
- Evidence of injection of charge carriers from quantum dots to the substrate

We describe a new experimental pump-probe methodology where a 2D delay-line detector enables fast (ns) monitoring of a narrow XPS spectrum in combination with a continuous pump laser. This has been developed at the TEMPO beamline at Synchrotron SOLEIL to enable the study of systems with intrinsically slow electron dynamics, and to complement faster measurements that use a fs laser as the pump. We demonstrate its use in a time-resolved study of the surface photovoltage of the m-plane ZnO (101¯0) surface which shows persistent photoconductivity, requiring monitoring periods on ms timescales and longer. We make measurements from this surface in the presence and absence of chemically-linked quantum dots (QDs), using type I PbS and type II CdSe/ZnSe (core/shell) QDs as examples. We monitor signals from both the ZnO substrate and the bound QDs during photoexcitation, yielding evidence for charge injection from the QDs into the ZnO. The chemical specificity of the technique allows us to observe differences in the extent to which the QD systems are influenced by the field of the surface depletion layer at the ZnO surface, which we attribute to differences in the band structure at the interface.

106

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 641, November 2015, Pages 320-325
نویسندگان
, , , , , , , , , , , , , ,