Quantum Dots

Why in news?

• The 2023 Nobel Prize in chemistry was awarded to Moungi G. Bawendi, Louis E. Brus and Alexei I. Ekimov for the discovery and synthesis of quantum dots.

About Quantum Dots

• Quantum dots are particles that are a few nanometres wide.
• The physical and optical properties of quantum dots, such as their electronic bandgap and emission wavelength (colour), depend on their size. As the size of a quantum dot changes, so does its behavior, making them highly tunable for specific applications.
• Quantum dots can emit light when excited with energy (e.g., from a laser or other light source). The emitted light’s color, or wavelength, can be precisely controlled by adjusting the size of the quantum dot. This property is crucial for applications like displays and lighting.
• Due to their small size (typically between 2 and 10 nanometers in diameter), electrons in quantum dots are confined in a three-dimensional space (Quantum Confinement). Typically, electrons move within a relatively spacious area outside the nucleus of an atom. However, as particle size drastically decreases, electrons experience increasing constraints, leading to the manifestation of these peculiar quantum effects.

Applications of Quantum Dots

• Displays and Lighting: Quantum dots can enhance the color and efficiency of displays and lighting. They are used in QLED (Quantum Dot Light Emitting Diode) displays to produce vivid and energy-efficient colors in televisions, monitors, and mobile screens.
• Biomedical Imaging: Quantum dots are employed as fluorescent markers in biological imaging and diagnostics. They can track and label specific cells or molecules in biological samples with high precision.
• Solar Cells: Quantum dots can be used in solar cells to improve their efficiency. They can capture a broader spectrum of light and convert it into electricity more effectively than traditional materials.
• Quantum Computing: Quantum dots can serve as qubits, the fundamental units of quantum information in quantum computing. They hold promise for quantum information processing due to their controllable quantum states.
• Photodetectors and Photocatalysis: Quantum dots are used in photodetectors for sensing light and in photocatalysis to facilitate chemical reactions when exposed to light. These applications have environmental and energy-related uses.
• Drug Delivery: Quantum dots can be utilized in drug delivery systems. They can transport drugs to specific targets in the body, improving the precision and efficacy of treatments.
• Security Tags: Quantum dots can be embedded in security tags or labels for anti-counterfeiting purposes. They are challenging to replicate due to their unique optical properties.
• Quantum Dot Telecommunications: Quantum dots are investigated for their potential in quantum communication systems, which offer enhanced security in data transmission.
• Infrared Detection: Quantum dots can be engineered to detect infrared light, making them valuable for applications such as night vision technology and thermal imaging.
• Environmental Sensing: Quantum dots can be employed as sensors for detecting various environmental parameters like temperature, humidity, and pollutants.

PRACTICE QUESTION:

Which of the following is/are applications of Quantum dots?

1. Enhance the color and efficiency of displays and lighting.
2. In drug delivery systems.
3. As fluorescent markers in biological imaging and diagnostics.

Select the correct answer using the code given below:

1. 1 only
2. 1, 2 and 3
3. 2 and 3 only
4. 3 only

Answer