High efficiency ultrathin CdTe film is an excellent candidate for reliable, efficient, stable and low cost solar cells. In this paper, a high efficiency CdS/CdTe solar cell has been studied by using ...ADEPT 1D simulation tool. The proposed device has been simulated with a reduced CdTe absorber layer thickness and a ZnTe layer as back surface field (BSF) which substantiates sensible energy conversion efficiency. The investigation into the simulation results showed that the conversion efficiency with BSF layer and 1 μm thick CdTe absorber is 8.24% more as compared to the conventional CdTe cells (without BSF layer). Reduction of minority carrier recombination loss due to the insertion of BSF layer at the back contact in ultra-thin CdS/CdTe cells has also been investigated. The results depict that CdTe cell with BSF layer is responsible for increasing the quantum efficiency. However, the proposed structure of ZnO/CdS/CdTe/ZnTe demonstrates the highest efficiency of 24.66% (V
oc
= 946.51 mV, J
sc
= 34.40 mA/cm
2
and FF = 75.72%) under global AM1.5G illumination spectra.
The article comprises numerical data of distinct semiconductor materials applied in the sketch of a CdTe absorber based ultrathin film solar cell. Additionally, the contact layer parametric values of ...the cell have been described also. Therefore, the simulation has been conducted with data related to the hetero-structured (n-ZnO/n-CdS/p-CdTe/p-ZnTe) semiconductor device and a J–V characteristics curve was obtained. The operating conditions have also been recorded. Afterward, the solar cell performance parameters such as open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), and efficiency (η) have been investigated and compared with reference cell.
ZigBee is a wireless standard based on IEEE 802.15.4 specification for a set of communication protocols. It is intended for remote control and sensor applications. ZigBee is designed to use low power ...digital radio signals for personal area networks which require secure networking. The use of the ZigBee protocol accommodates and facilitates for carrying out secure communications, ciphering frames and controlling devices, protecting establishment and transport of cryptographic keys. This paper presents a security enhancement technique for ZigBee by modifying the MAC layer. This work also serves enhanced security processing in Network and Application layer of ZigBee protocol. The improved security mechanism of Network and Application layer has been developed using Radio Frequency Identification (RFID) and proxy firewall techniques respectively. Riverbed v17.5 is used to simulate and scrutinize different ZigBee layers to enrich security. The result of this study provides reliable and stable ZigBee protocol scheme to end users. Furthermore, the paper shows security adoption in MAC, Network, and Application layers of ineligible nodes, packets, and data blocks. The benefits of the work include end-to-end security with confidentiality, data packet integrity, message and device authentication.
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