به تازگی انرژیهای تجدیدپذیر به دلیل مزیتهای غالب خود در مقایسه با انرژیهای فسیلی، توجه زیادی را به خود جلب کردهاند. مصرف برق جهان بین 12 تا 13 ترا وات در سال است و با رشد جمعیت افزایش مییابد. منابع اصلی برای مصرف انرژی سوختهای فسیلی هستند که با توجه به انتشار بیش از حد گازهای گلخانه ای، استفاده از آنها به زیان محیط زیست میباشد. یک جایگزین مناسب برای مصرف سوختهای فسیلی استفاده از فتوولتاییک (PV) یا سلولهای خورشیدی است. انـرژی خورشیـدی که در یک سـاعت به اتمسفـر میرسد برای تأمیـن تقاضای انرژی یک سال جهان کافی است. بزرگترین عامل بازدارنده برای استفاده از سلولهای خورشیدی قیمت اولیه آن است. اما در دراز مدت پول سرمایهگذاری شده میتواند به دلیل دوام سلولهای خورشیدی بازگردد.
وبسایت مهندسی الکترونیک و کامپیوتر
ترجمه مقاله Integrated Optical Devices of InGaAsP-InP Heterojunction Phototransistor and InnerStripe Light-Emitting Diode
Abstract - New integrated optical devices combining an InGaAsP/InP HPT and an inner-stripe LED are proposed and their fabrication processes are described. The device functions of light amplification, optical bistability, and optical switching are demonstrated in the 1-um wavelength region.
I. INTRODUCTION: MONOLITHIC integration of well-developed discrete devices such as lasers, light-emitting diodes (LED’s), phototransistors, p-i-n diodes, and avalanche photodiodes (APD’s) has been drawing much attention for better performance and higher reliability [ 11, . By integration, on the other hand, new functions which cannot be expected for the discrete optoelectronic devices can be realized utilizing the optical or electrical interactions between two or more optoelectronic devices -[ ll].
نویسنده: حمیدرضا ارزبین
Abstract - We perform the numerical analysis of a CIGS solar cell parameters such as open circuit voltage, short circuit current, maximum power, fill factor, and external quantum efficiency as a function of absorber layer band gap. These parameters are known to be the key parameters of a solar cell to determine its performance. We change the band gap of the CIGS absorber layer by changing its alloy composition. ATLAS SILVACO is used to construct and simulate the CIGS solar cell structure with standard AM1.5 spectra. The open circuit voltage and the maximum power increase almost linearly with the band gap. However, the change in short circuit current and the fill factor with the CIGS bandgap does not show any formal relation. We found that the change in fill factor due to the band gap change is not significant compared to the change in open circuit voltage.
نویسنده: حمیدرضا ارزبین
ترجمه مقاله Improving the performance of a multi-junction solar cell by optimizing BSF, base and emitter layers
Abstract - Reducing the recombination rate and increasing the photo-generation rate play a very significant role in improving the performance of the solar cells. In this research, AlGaAs has been used instead of GaAs in emitter layer with reduction in thicknesses of the base in order to decrease the recombination rate and increase the efficiency of the proposed solar cell. In addition, tunnel junction, buffer junction and BSF layers have been optimized to achieve higher efficiency. The efficiency can be improved by selecting optimal thickness of the materials because of the increase in photo-generation rate and absorption rate, improving transparency of the tunnel area and reducing the recombination rates of the solar cells. The results showed that after optimization, JSC (short circuit current density), VOC (open circuit voltage) and the η (conversion efficiency) of the solar cell are clearly increased. Also, the results of simulation were compared to the other designs in order to compare its performance. In the proposed structure, values of Voc= 2.52 V, Jsc= 29.09 mA/cm2, FF=86.49% and η= 62.04% (1 sun) are obtained under AM1.5G illumination.
نویسنده: حمیدرضا ارزبین
ترجمه مقاله Efficiency improvement of ARC less InGaP/GaAs DJ solar cell with InGaP tunnel junction and optimized two BSF layer in top and bottom cells
An optimized BSF (Back Surface Field) is a key layer for a multi junction or single junction solar cell. In this work, two BSF layers with different thicknesses have been used in the upper and the lower cell and simulations have been done using the Silvaco ATLAS numerical modelling tools. It has been also found that in under the current matching condition with thinner upper BSF layers (160 nm, 30 nm) and a thicker lower BSF layer (1000 nm, 30 nm), JSC short circuit current density and VOC open circuit voltage and conversion efficiency solar cell is improved. Major steps of simulation and its description and results have been compared to the previously published data in order to describe accuracy of the results. By selecting the best thickness of BSF layer, the efficiency can be increased up to 15% which happens because of increase in photo-generation rates and absorption in the solar cells. This article shows some characteristics of the proposed dual junction solar cell such as photo-generation rate, short circuit current density, open circuit voltage and efficiency of the device relative to thickness of BSF layers and change in materials of tunnel junction. The results show that in case of increase in thickness of BSF, efficiency is also increased. The highest efficiency is obtained in thickness of 160 nm, then the efficiency is decreased. The values of Jsc = 23.36 mA/cm2, Voc = 2.43 V, FF = 86.76% and η = 47.78% (1 sun) have also been obtained under AM1.5G illumination in the proposed structure which shows improvement in performance of the proposed device.