LAN zhaojue, a doctoral student in associate professor rodin's research group, has published an academic paper in the journal Science Advances as the lead author

2017-09-12

Recently, the department of electrical and electronic engineering rodin, an associate professor at group level 2016 doctoral LanZhaoJue as the first author in Science Advances (12.804) IF: the journal titled Near infrared and visible light dual - mode organic photodetectors academic papers, the south university of Science and technology department of electrical and electronic engineering, an associate professor and rodin Zhu Furong physics department of the Hong Kong Baptist university professor of the corresponding author for the article.

                                                                                     

                                                         Photo: blue administration, PhD candidate, class of 2016

In recent years, the photoelectric detection technology based on thin film semiconductor has shown a good application prospect in many fields such as environmental detection, health diagnosis and security monitoring. Organic photodetector has the advantages of high responsivity, solution-processable, and adjustable spectrum, and has the potential to be the next generation of high-performance optical detection technology.

Traditional photodetectors have only one working mode and the wavelength window of the detection spectrum cannot be adjusted. The research group proposes a dual-mode/dual-band tunable organic photodetector of near-infrared and visible light, whose device structure mainly includes visible light absorption layer, optical spacer layer and near-infrared absorption layer. It is found that the organic thin film photodetector based on this structure has two modes of light response: near-infrared and visible. Under the irradiation of nir light, photocurrent is generated from the nir absorption layer. Its working principle is that under the negative bias pressure, the interface between the organic film layer and the cathode electrode is trapped, resulting in nir response carrier injection. Under the irradiation of visible light, the photocurrent is generated from the visible light absorption layer. The principle is that under the positive bias pressure, the carrier injection of visible light response occurs at the interface between the anode electrode and the organic film layer. Driven by negative bias, the dual-mode optical detector displays a blind near-infrared response of visible light. Under the driving of positive bias, it only detects visible light, but has no response to near infrared. The response of incident light in both short wave and long wave is up to 10 A/W.

                                                                                  

Figure: optical responsivity spectrum and simulated optical distribution of dual-mode detectors: (A) responsivity under negative bias, (B) responsivity under positive bias, and (C) depth distribution of photogenerated carriers in the device.

Compared with traditional single-mode photodetectors, high-performance near-infrared and visible dual-mode/dual-band detectors offer new possibilities for optical detection technology. The organic thin film preparation process based on solution processing has the advantages of low cost, large area manufacturing and softness. The dual-mode organic photodetector proposed in this work can be used in different wavelength imaging, environmental pollution detection, medical health and security monitoring applications.

LAN zhaojue, the first author of the paper, is a 2016 undergraduate student majoring in optoelectronic information science and engineering in the department of electronic and electrical engineering, southern university of science and technology. LanZhaoJue students to participate in the 11th Asian Conference on Organic Electronics and titled Near infrared and visible light dual - mode Organic photodetectors academic report, Poster for the assembly of the Journal of Materials Chemistry A Poster Prize award.

Links to papers:

https://advances.sciencemag.org/content/6/5/eaaw8065