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Your search keyword '"Hao, Xiaojing"' showing total 2 results
Start Over Author "Hao, Xiaojing" Publication Type Reports
2 results on '"Hao, Xiaojing"'

1. Influence of Organic Spacer Cation on Dark Excitons in 2D Perovskites

Author

Bailey, Christopher G., Gillan, Lara V., Lee, Minwoo, Sloane, Nicholas, Liu, Xu, Soufiani, Arman Mahboubi, Hao, Xiaojing, and McCamey, Dane R.

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics
Abstract

The organic spacer cation plays a crucial role in determining the exciton fine structure in two-dimensional (2D) perovskites. Here, we use low-temperature magneto-optical spectroscopy to gain insight into the influence of the organic spacer on dark excitons in Ruddlesden-Popper (RP) perovskites. We show that by using modest magnetic field strengths (<1.5 T), the spin-forbidden dark exciton state can be identified and its emission properties significantly modulated through the application of in-plane magnetic fields, up to temperatures of 15 K. At low temperatures, an increase in collected photoluminescence efficiency of >30% is demonstrated, signifying the critical role of the dark exciton state for light-emitting applications of 2D perovskites. The exciton fine structure and the degree of magnetic-field-induced mixing are impacted by the choice of organic spacer cation, with 4-methoxyphenethylammonium (MeO-PEA) showing the largest effect due to larger bright-dark exciton splitting. Our results suggest that dark excitons preferentially form biexcitons depending on the choice of spacer. We distinguish between interior (bulk) and surface dark-exciton emission, showing that bright-dark exciton splitting differs between the interior and surface. Our results emphasize the significance of the organic spacer cation in controlling the exciton fine structure in 2D perovskites and have important implications for the development of optoelectronic technology based on 2D perovskites.

Published
2023
Full Text
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2. Integrating Reading and Writing in EFL Composition in China.

Author

Hao, Xiaojing and Sivell, John

Abstract

Research suggests that the current division between reading and writing instruction for Chinese English as a Second Language (ESL) students, the lack of authentic communication that typically exists in ESL contexts, and difficulties with sequencing teaching-learning activities combine to hinder the development of writing skills. The paper suggests that writing teachers must understand that there is much more involved in writing than the final copy turned in by students. It recommends integrating reading and writing in ESL education, noting that reading and writing are interactive. Writing teachers must move beyond giving students a topic to write on and then grading the final product. They must include plenty of process work, from reading to writing, so students will progress from reading, to discussing and analyzing, to writing. Writing instruction is effective when contextualized through background reading related to real-life interests. This allows students to understand the purpose of the relationship between reading and writing. This integration allows educators to teach more effectively by dealing with reading and writing simultaneously and students to write more effectively in an authentic context. Reading strategies that students learn early in the process will become part of their writing strategies later on. (Contains 15 references.) (SM)

Published
2002

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