3. The efficiency of a single p-n junction solar cell in converting solar energy to electricity depends on the energy band gap of the specific solar cell material, as shown in the figure below. Based on results from question #3 above and also searching the internet if necessary, give a physical explanation of the bell-shape dependence of solar cell efficiency on band gap energy, Eg. That is, why efficiency of solar cell initially increases as a function of band gap, peaks at about 1.2-1.4 eV, and then decreases as band gap further increases? 50 Si InP 40 GaAs CdTe Ge 30- C-1000 20 Cds 10 2 3 Bandgap energy, E, (eV) (%)Efficiency

3. The efficiency of a single p-n junction solar cell in converting solar energy to electricity depends on the energy band gap of the specific solar cell material, as shown in the figure below. Based on results from question #3 above and also searching the internet if necessary, give a physical explanation of the bell-shape dependence of solar cell efficiency on band gap energy, Eg. That is, why efficiency of solar cell initially increases as a function of band gap, peaks at about 1.2-1.4 eV, and then decreases as band gap further increases? 50 Si InP 40 GaAs CdTe Ge 30- C-1000 20 Cds 10 2 3 Bandgap energy, E, (eV) (%)Efficiency

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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Similar questions

What is band bending, and why does it happen when two dissimilar materials (for example, p-type and n-type semiconductors; metal and semiconductor) come into contact?
Determine the thermal equilibrium electron and hole concentrations in a compensated n- type semiconductor. Consider a silicon semiconductor at T = 300°K in which Na = 10° cm³ and Na = 3 x 105 cm. Assume that n; =1.5 x 10º cm?.
8. Each of the three insulators forming a string has a self capacitance of C farad The shunt capacitance of each insulator is 02C to earth and 0-1 C to line. A guard-ring increases the capacitance of line of the metal work of the lowest insulator to 0-3 C. Calculate the string efficiency of the arrangement: )with the guard ring. (7) without guard ring. 10 95% () 86 13%|
Subject: Electronics Engineering Solve no 6
a) Explain the band structure of an electrical conductor (metal), a semiconductor, and an insulator at 0 K by showing the valence and conduction bands and fermi energy levels. Explain how the electrical conduction takes place in these three types of materials. Give an example for each type of material. b)Explain what n and p-type semiconductors are using their band structures.
7/ What is the semiconductor constant for Silicon? a. 0.7 b. 0.3 c. 2 d. 1
(i) In an intrinsic semiconductor, the electrical conductivity takes into account the contribution of electron and hole current. (ii) Furthermore, every electron that is promoted across the band gap leaves behind a hole in the valence band, that is, n = p = ni. The above statements are: A. True B. False D. No idea C. Neither True nor False E. Cannot be determined Other:
1. Discuss the physical phenomena that cause the theoretical limit of a PV cell. 2. What are the technological losses that are associated with efficiency limit concept PV cells? Draw a PV cell cross-section to indicate these losses. What is the main reason for stacking multiple semiconductor junctions (of different materials)? What is the main operational concept behind this technology? Classify PV cells by origin of built-in potential, Material, and Technology. Discuss the operational principles of the anti-reflection coating in PV cells. Please consider using the following terms: interference, destructive, constructive, coating material, and coating thickness. 6. Discuss the benefit of having a textured PV cell surface. 3. 4. 5.
5) Germanium doped with 1024 m3 Al atoms is a semi-conductor at room temperature and each Al atom creates a charge carrier. a) Is the material obtained a p-type or an n-type semiconductor? b) Calculate the electrical conductivity of this material at room temperature, considering that the electron and hole mobilities are respectively 0.1 and 0.05 m?/V.s.
B5
Where is the Fermi-level of a boron doped Si semiconductor at 77 K, 300 K, and 600 K at full activation of dopants? The Fermi-level shall be related to the intrinsic Fermi-level Ej. (NA = 107 cm3, Eg(Si) = 1.12 ev, m,* = 0.3mo, m,* = 0.5mo.) Sketch the solution.
A crystalline silicon photovoltaic cell has an open circuit voltage of 0.5V and a short circuit current of 1.8 A at Standard Test Conditions. What is the maximum output power at Standard Test Conditions and at a cell temperature of 50oC? What is the percentage decrease in power per oC? Assume a Fill Factor of 0.70 at 25oC. (As a rule of thumb for crystalline silicon solar cells, the increase in short circuit current is about 0.058% per oC while the decrease on open circuit voltage is 0.30% per oC and decrease in the fill factor is by 0.15% per oC).