Lecture

Solar Cell Efficiency: Influence of Energy Gap

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

MICRO-312: Physics of semiconductors devices

Les étudiants savent expliquer la physique des composants semiconducteurs, tels que diodes, transistors et composants MOS. Ils les utilisent dans des circuits électroniques fondamentaux tels qu'inverseurs et ampli. ...

Description

This lecture discusses the influence of the energy gap on the efficiency of solar cells, focusing on two types: monocrystalline silicon and amorphous silicon. The instructor compares the energy gaps of both materials, noting that the monocrystalline silicon has a gap of 1.1 eV and a built-in voltage of 0.88 V, while the amorphous silicon has a higher gap of 1.7 eV and a built-in voltage of 1.36 V. The lecture highlights the qualitative differences in losses due to transparency and thermalization for both types of cells. It explains how the energy gap affects the absorption of solar energy, with specific emphasis on the wavelengths that are not absorbed and the resulting thermal losses. The instructor also presents graphical representations of the efficiency under standard conditions, illustrating how the energy gap influences the overall performance of solar cells. The discussion concludes with insights on optimizing energy recovery in single-junction solar cells and the potential for improved efficiency with multi-junction designs.

Instructor

Pierre-André Besse

Teaching & PhD Past EPFL PhD Students Klaus Ehrmann Courses La science quantique : une vision singulière MICRO-444 Students understand the characteristics of quantum science. They master the formalism and use it in basic quantum systems: quantum wells, wires, dots or qubits. Physics of semiconductors devices MICRO-312 The students are able to explain the physics of semiconductor devices like diodes, transistors, and MOS devices. They use such devices in fundamental electroni

Official source

Ontological neighbourhood

Energy engineering

Solar power: Topics in solar power

Related concepts (32)

Solar-cell efficiency

Solar-cell efficiency refers to the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity by the solar cell. The efficiency of the solar cells used in a photovoltaic system, in combination with latitude and climate, determines the annual energy output of the system. For example, a solar panel with 20% efficiency and an area of 1 m2 will produce 200 kWh/yr at Standard Test Conditions if exposed to the Standard Test Condition solar irradiance value of 1000 W/m2 for 2.

Solar cell

A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical phenomenon. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Individual solar cell devices are often the electrical building blocks of photovoltaic modules, known colloquially as solar panels.

Multi-junction solar cell

Multi-junction (MJ) solar cells are solar cells with multiple p–n junctions made of different semiconductor materials. Each material's p-n junction will produce electric current in response to different wavelengths of light. The use of multiple semiconducting materials allows the absorbance of a broader range of wavelengths, improving the cell's sunlight to electrical energy conversion efficiency. Traditional single-junction cells have a maximum theoretical efficiency of 33.16%.

Photovoltaic system

A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct to alternating current, as well as mounting, cabling, and other electrical accessories to set up a working system. It may also use a solar tracking system to improve the system's overall performance and include an integrated battery.

Photovoltaics

Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially used for electricity generation and as photosensors. A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop-mounted, wall-mounted or floating.

Related lectures (64)

Solar Cells: Efficiency and Losses

Covers the operation, efficiency, and losses associated with solar cells, including the concept of hybrid photovoltaic thermal panels.

Standard Cell Processing: PERC, PERL and PERT

Explores standard cell processing techniques for silicon solar cells, including PERC, PERL, and PERT structures, focusing on efficiency and manufacturing challenges.

Solar Energy: Basics in Thermal Transport and Solar Systems

Covers the basics of energy states in matter, thermal transport, and solar systems, emphasizing the importance of electrochemistry in solar energy applications.

Photovoltaics and Fusion Energy

Explores the role of photovoltaics in the energy transition and the potential of fusion energy for sustainable power generation.

High Efficiency Solar Cells