Defect Engineering in Few-Layer Phosphorene

Ankur Sharma; Bo Wen; Boqing Liu; Ye Win Myint; Han Zhang; Yuerui Lu

doi:10.1002/smll.201704556

Defect Engineering in Few-Layer Phosphorene

Small. 2018 Apr;14(16):e1704556. doi: 10.1002/smll.201704556. Epub 2018 Mar 23.

Authors

Ankur Sharma¹, Bo Wen^{1

2}, Boqing Liu¹, Ye Win Myint¹, Han Zhang², Yuerui Lu¹

Affiliations

¹ Research School of Engineering, College of Engineering and Computer Science, the Australian National University, Canberra, ACT, 2601, Australia.
² SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, P. R. China.

PMID: 29571222
DOI: 10.1002/smll.201704556

Abstract

Defect engineering in 2D phosphorene samples is becoming an important and powerful technique to alter their properties, enabling new optoelectronic applications, particularly at the infrared wavelength region. Defect engineering in a few-layer phosphorene sample via introduction of substrate trapping centers is realized. In a three-layer (3L) phosphorene sample, a strong photoluminescence (PL) emission peak from localized excitons at ≈1430 nm is observed, a much lower energy level than free excitonic emissions. An activation energy of ≈77 meV for the localized excitons is determined in temperature-dependent PL measurements. The relatively high activation energy supports the strong stability of the localized excitons even at elevated temperature. The quantum efficiency of localized exciton emission in 3L phosphorene is measured to be approximately three times higher than that of free excitons. These results could enable exciting applications in infrared optoelectronics.

Keywords: activation energy; defect emissions; infrared; localized excitons; phosphorene.