Surface Plasmonic Silver Nanoparticles Enhanced ZnSe Nanoribbons Optoelectronic Devices Properties

ZnSe is an important ?-? compound semiconductor material with wide direct band-gap of?2.70 eV at room temperature. It has important applications in photodetectors, photovoltaic and luminescent devices. Silicon is of special interest due to its key role in the modern semiconductor industry. Nevertheless, the low emission efficiency obstructs its applications in light emission devices. Enhancing the properties of the ZnSe/Si nano-heterostructures is significant. Noble metal nanoparticles with localized surface plasmon resonance ?LSPR? have recently attracted much wide attention for possible applications. They may greatly improve light trapping ability without obviously increasing the physical thickness of the absorption layers. This is especially important for nanstructure-based optoelectronic devices, possessing potential advantages of more efficient charge collection and enhanced light trapping and absorption ability.In this work, we used silver ?Ag? nanoparticles to modify ZnSe nanoribbons by solution method, and utiliz surface plasmon resonance effect to increase the light absorption of ZnSe nanoribbons. After the decoration of Ag nanoparticles, the light absorption of ZnSe nanoribbons were improved, and more suitable for the preparation of photoelectric devices. The main achievements in our job are as following:1. The p-type ZnSe nanoribbons have been accomplished by using antimony as the p-type dopant via a thermal evaporation method. The result reveals that the ZnSe:Sb nanoribbons are clean and uniform, and nanoribbons are zinc blende single crystals.2. The different sizes of Ag nanoparticles were successfully prepared by the Lee-Meisel method, namely,39 nm,48 nm,64 nm, respectively. It is interesting to note that when the size of Ag nanoparticles increases, an obvious red-shift was observed. After mixing different sizes of nanoparticles, an obvious red-shift was observed compared to single nanoparticles.3. Optical analysis reveals that the absorption of ZnSe:Sb NRs was increased after the decoration of the Ag nanoparticles with strong LSPR. These characters can enhance the performances of the devices.4. The heterojunction devices based on ZnSe/Si were constructed successfully. We experimentally demonstrated that the device performance can be promoted after modifying Ag nanoparticles. And device modified with 39+64 nm Ag nanoparticles was excellent. The short-circuit photocurrent density of the ZnSe/Si heterojunction solar cell was improved by 57.6% from 11.75 to 18.52 mA/cm² compared to the one that was without Ag NPs. Meanwhile, the responsivity and detectivity of ZnSe:Sb NRs/Si heterojunction device increased from 117.2 to 184.8 mAW^-1, and 5.86×10¹¹ to 9.20×10¹¹ cmHz^1/2W^-1, respectively.