Question 42 from UPSC CSE 2017 - Science and
Technology

Question

Organic Light Emitting Diodes (OLEDs) are used to create digital displays in many devices. What are the advantages of OLED displays over Liquid Crystal displays?
1. OLED displays can be fabricated on flexible plastic substrates.
2. Roll-up displays embedded in clothing can be made using OLEDs.
3. Transparent displays are possible using OLEDs.
Select the correct answer using the code given below:

Accepted Answer

Correct Option: C. 1, 2, and 3

Strategy: Evaluate each of the three statements about OLED technology. Confirm that OLEDs can be fabricated on flexible substrates, enabling rollable and wearable displays. Verify their potential for transparency. Conclude that all statements are accurate, making option C the correct choice.

Key Info: Organic Light Emitting Diodes (OLEDs) are a type of display technology that employs organic compounds which emit light when an electric current is applied. Unlike Liquid Crystal Displays (LCDs), which require backlighting, OLEDs are self-luminous.

- **Flexibility:** OLEDs can be produced on flexible substrates, such as thin plastic sheets, enabling the creation of bendable, foldable, or rollable displays. This is not possible with conventional LCDs, which rely on glass substrates and rigid backlight systems.
- **Wearable and Roll-up Displays:** Due to their thinness, lightweight nature, and flexibility, OLEDs allow for innovative applications such as roll-up screens, foldable smartphones, and wearable displays embedded in textiles and clothing. Commercial and prototype devices have demonstrated displays that can be rolled or folded without damage.
- **Transparency:** OLED panels can be engineered using transparent electrodes and emissive layers, permitting partial or complete light transmission when the screen is not displaying content. This enables transparent display applications such as heads-up displays, smart windows, and augmented reality screens.

**Additional OLED Advantages:**
- Higher contrast ratios (true blacks) due to pixel-level control
- Wider viewing angles compared to LCDs
- Faster response times for high-refresh-rate and motion content

**Limitations:**
- Typically more expensive to manufacture than LCDs
- Susceptibility to moisture and oxygen; require encapsulation
- Potential for image retention or burn-in over extended use

**Applications:**
- Smartphones
- Televisions
- Smartwatches
- Augmented reality devices
- Automotive displays
- Innovative electronic textiles

Answer

Option A: 1 and 3 only

Answer

Option B: 2 only

Answer

Option D: None of the above statements is correct