Real Life Applications of Photoelectric Effect

Last Updated : 03 May, 2024

The photoelectric effect is a phenomenon in which electrons are emitted from a material when it is exposed to light or electromagnetic radiation of sufficient energy. In simpler terms, it’s when light shining on a surface causes the emission of electrons from that surface.

When a metal is exposed to light, metal emits electrons from its valence shell. This is called photoelectric effect. The real life applications of photoelectric effect is used in various optoelectronic devices, in photodiodes, photovoltaic cells etc. In this article we will learn in details about various photoelectric effects.

Applications of Photoelectric Effect

Photoelectric effect is a phenomenon in which electrons are emitted from a material (such as a metal) when it is exposed to electromagnetic radiation, typically light. The real life applications of photoelectric effect in daily life is explained below:

Solar Panel

Solar panel convert light energy into electricity with the help of Photoelectric effect. When the photons of sunlight falls on the semiconductor installed on the solar panel, they displaces the electrons from their atoms and movement of electron causes generate electricity.

Light Sensors

Photo cells are used in light sensors, when light falls on the photo cells it creates electric energy which can be used to trigger various switches like automatic light on-off system.

Digital Cameras

CMOS (Complementary Metal-Oxide-Semiconductor) or CCD (Charge-Coupled Device) sensor is used in digital camera which uses the principles of photo electric effect which converts light energy into electrical signals. These electrical signals are used to create digital image.

Barcode Scanners

Photodiodes are used in the scanner when it placed on the barcode intensity of the light changes. Photoelectric effect is used to convert these lights into digital which can be used identify the product.

Smoke Detector

Light source and a photosensitive sensor are used in the smoke detector to detect the fire. When smoke enter inside the case of sensor it scatters light on the sensor which triggers the alarm and started sprinkling water.

Security Systems

Security system uses photoelectric sensor to detect the motion of an object. It works by emitting light rays and measure it’s reflection. Changes in the intensity of the reflected light indicates the motion of the object or presence of the any object which trigger the alarms and alert the security personnel.

X-Ray Photoelectron Spectroscopy (XPS)

X-Ray Photoelectron Spectroscopy involves irradiating a surface with x-rays and measuring the kinetic energy of the electrons that are released. It is used to learn important features of a surface’s chemistry, such as elemental composition, chemical composition, the empirical formula of compounds, and chemical state, can be acquired.

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Applications of Photoelectric Effect in Medical Field

X-ray Imaging: The photoelectric effect is utilized in X-ray imaging systems to produce high-resolution images of the human body. When X-rays are directed at a patient’s body, some of the X-ray photons undergo the photoelectric effect, leading to the absorption of X-ray photons by the body tissues. The degree of X-ray absorption depends on the atomic number and density of the tissues, allowing for the generation of contrast between different tissues in the resulting X-ray image. X-ray imaging is commonly used for diagnosing fractures, detecting tumors, and examining internal organs.

Computed Tomography (CT) Scans: CT scans utilize the photoelectric effect to create detailed cross-sectional images of the body. In CT scanning, X-ray beams are directed at the patient’s body from multiple angles, and detectors measure the intensity of X-ray photons that pass through the body. The photoelectric effect contributes to the attenuation of X-ray photons as they pass through different tissues, providing information about tissue density and composition. CT scans are used for diagnosing conditions such as tumors, trauma, and vascular diseases.

Nuclear Medicine Imaging: In nuclear medicine imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), radioactive tracers are introduced into the body, and gamma-ray emissions are detected using specialized detectors. The photoelectric effect contributes to the attenuation of gamma-ray photons as they pass through body tissues, allowing for the localization and imaging of radioactive tracers within the body. Nuclear medicine imaging is used for diagnosing cancer, heart disease, and neurological disorders.

Use of Photoelectric Effect in Solar Panel

Photovoltaic Cells: Solar panels consist of photovoltaic cells, also known as solar cells, which are typically made of semiconductor materials such as silicon. When sunlight strikes the surface of a solar cell, photons (particles of light) with sufficient energy can dislodge electrons from the atoms in the semiconductor material, creating electron-hole pairs.

Generation of Electric Current: The dislodged electrons create an electric current when they flow through an external circuit connected to the solar panel. This flow of electrons constitutes electricity, which can be harnessed for various applications, such as powering homes, businesses, or electronic devices.

Semiconductor Structure: The semiconductor material used in solar cells is carefully engineered to facilitate the photoelectric effect. The material has a bandgap energy that corresponds to the energy of photons in sunlight, allowing them to be absorbed efficiently. Additionally, the semiconductor structure ensures that the generated electrons and holes are separated and directed along the electrical circuit to produce a useful electrical current.