Lesson 2 QUIZ
Question: What are the three main types of materials based on electrical
conductivity?
● Answer: The three main types are conductors, insulators, and
semiconductors.
Question: What is the difference between n-type and p-type silicon?
● Answer: N-type silicon is doped with pentavalent atoms (like phosphorus)
that donate extra electrons, while p-type silicon is doped with trivalent
atoms (like boron) that create holes by accepting electrons.
Question: Describe the structure of a p-n junction semiconductor.
● Answer: A p-n junction is formed by sandwiching p-type and n-type
semiconductors together, creating a depletion zone where electrons and
holes recombine.
Question: How do solar cells convert sunlight into electricity?
● Answer: Solar cells convert sunlight into electricity by absorbing photons,
which excite electrons and create an electric current through the p-n
junction.
Question: What is the significance of the energy band structure in
semiconductors?
● Answer: The energy band structure determines the electrical properties of
semiconductors, including their conductivity and the energy required to
move electrons from the valence band to the conduction band.
Question: What is the typical thickness of a solar cell?
● Answer: The typical thickness of a solar cell is between 150 to 200
micrometers.
Question: What is the purpose of doping in semiconductor fabrication?
● Answer: Doping is used to intentionally add impurities to silicon to
enhance its electrical conductivity by creating n-type or p-type materials.
Question: What is the process of surface texturing in solar cell fabrication?
● Answer: Surface texturing involves etching the surface of the silicon wafer
to reduce reflectivity and increase light absorption.
Question: What is the role of the encapsulant in solar modules?
● Answer: The encapsulant protects solar cells from environmental damage,
such as moisture and dirt, and is typically made of ethyl vinyl acetate
(EVA).
Question: How is the n-type layer added to a solar cell during fabrication?
● Answer: The n-type layer is added by exposing the p-type silicon wafer to
a phosphorus-doped gas, which deposits the n-type material on the
surface.
Question: What is the function of busbars in solar cells?
● Answer: Busbars are metallic strips that collect and conduct the electric
current generated by the solar cells to the external circuit.
Question: What is packing density in the context of solar modules?
● Answer: Packing density refers to the ratio of the area occupied by solar
cells to the total area of the solar module, affecting the module's
efficiency.
Question: What is hotspot heating in solar modules?
● Answer: Hotspot heating occurs when shaded or malfunctioning cells in a
solar module generate excess heat, potentially leading to damage or
failure.
Question: What does NOCT stand for, and why is it important?
● Answer: NOCT stands for Nominal Operating Cell Temperature, which
indicates the expected temperature of a solar cell under specific
conditions and is important for performance evaluation.
Question: How do you test the efficiency of a solar module?
● Answer: The efficiency of a solar module is tested by measuring its output
power under standard test conditions (STC) and comparing it to the
incident solar energy.
Question: What are common defects found in solar modules?
● Answer: Common defects include module delamination, junction box
failure, glass breakage, and cell cracks.
Question: What is the typical efficiency range for thin-film solar cells?
● Answer: The efficiency of thin-film solar cells typically ranges from 10% to
12%.
Question: What is the maximum theoretical efficiency of a single-junction solar
cell?
● Answer: The maximum theoretical efficiency of a single-junction solar cell
is about 33.5%.
Question: How does temperature affect the performance of solar cells?
● Answer: Higher temperatures generally decrease the voltage output of
solar cells, leading to reduced overall efficiency.
Question: What is the purpose of the glass layer in solar modules?
● Answer: The glass layer provides mechanical stability and protection
against environmental factors such as moisture and dirt.
Question: How are solar cells connected to form a solar module?
● Answer: Solar cells are connected in series and parallel configurations to
achieve the desired voltage and current output for the module.
Question: What is the significance of the fill factor (FF) in solar cells?
● Answer: The fill factor is a measure of the quality of the solar cell,
indicating the ratio of the maximum power output to the product of
open-circuit voltage and short-circuit current.
Question: What is the typical lifespan of solar cells?
● Answer: The typical lifespan of solar cells is around 20 to 30 years.
Question: What is the role of the junction box in solar modules?
● Answer: The junction box houses the electrical connections and bypass
diodes, protecting them from environmental damage and ensuring safe
operation.
Question: What advancements are being made in solar cell technology?
● Answer: Advancements include the development of multi-junction cells,
improved materials for higher efficiency, and innovative designs for better
thermal management.
