Gupta Anu, Chowdhury Rup K, Ray S K, Srivastava S K
Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
Nanotechnology. 2019 Oct 25;30(43):435204. doi: 10.1088/1361-6528/ab3382. Epub 2019 Jul 19.
The plasmon-enhanced photoresponse properties of a Ag nanoparticle decorated BiSe nanosheet (AGBS)/p-Si heterojunction device have been studied. The Ag nanoparticles, BiSe nanosheets, and AGBS nanocomposite are synthesized chemically. Microscopic investigations, ultimately of the AGBS nanocomposite, reveal that the BiSe nanosheets of thickness ∼20 nm and lateral dimension ∼1 μm are decorated with Ag nanoparticles of sizes 20-40 nm in the nanocomposite. The x-ray diffraction pattern of AGBS shows that apart from being in a metallic state, the Ag in the AGBS is also in the form of compounds with Bi, Se, and additionally O. This observation is further complemented by the x-ray photoelectron spectrum, which shows the presence of Ag and Ag states of Ag in AGBS. The UV-visible absorption spectra show the plasmonic peak of the Ag nanoparticles occurs at 420 nm; the peak is shifted to ∼500 nm in AGBS due to the modified dielectric environment of the nanoparticles. The AGBS/p-Si heterojunction shows excellent photoresponse properties, with a responsivity of 0.28 A/W, a fairly high detectivity of 4 × 10 Jones, and an EQE of 71% under 10 V reverse bias at a 500 nm wavelength. The plasmon enhanced photoresponse at the selective wavelength makes this material attractive for high performance optoelectronic devices.
研究了银纳米颗粒修饰的BiSe纳米片（AGBS）/p-Si异质结器件的等离子体增强光响应特性。通过化学合成法制备了银纳米颗粒、BiSe纳米片和AGBS纳米复合材料。对AGBS纳米复合材料进行的微观研究表明，在该纳米复合材料中，厚度约为20nm、横向尺寸约为1μm的BiSe纳米片上装饰着尺寸为20-40nm的银纳米颗粒。AGBS的X射线衍射图谱表明，AGBS中的银除了呈金属态外，还以与Bi、Se以及另外的O形成化合物的形式存在。X射线光电子能谱进一步证实了这一观察结果，该能谱显示AGBS中存在Ag以及Ag的不同价态。紫外-可见吸收光谱表明，银纳米颗粒的等离子体峰出现在420nm处；由于纳米颗粒介电环境的改变，该峰在AGBS中移至约500nm处。AGBS/p-Si异质结表现出优异的光响应特性，在500nm波长、10V反向偏压下，响应度为0.28A/W，探测率相当高，为4×10琼斯，外量子效率为71%。在选择性波长处的等离子体增强光响应使得这种材料对高性能光电器件具有吸引力。
