Polymer LED: Construction, Working, Advantages, and Disadvantages

This tutorial covers the basics of Polymer LEDs (PolyLEDs), including their construction, working principles, and applications. We’ll also explore their advantages and disadvantages.

As we know, polymers are lightweight and flexible materials. They are now being used as semiconductors in the development of LEDs, leading to the creation of Polymer LEDs.

The full form of Polymer LED is Polymer Light Emitting Diode. These LEDs have found numerous applications, including car bumpers, bulletproof vests, electronic newspapers, and color displays.

Polymer LED Construction & Working

Figure 1: Polymer LED Structure

Figure 1 shows the structure of a Polymer LED. It’s a special type of OLED (Organic Light Emitting Diode) that utilizes a polymer as one of its layers. As shown, it consists of a cathode, a polymer layer, an anode, and a substrate.

When an external voltage is applied, the Polymer LED emits light. It commonly employs polymers such as poly(p-phenylene vinylene) and polyfluorene in its construction, hence the name PolyLED.

Essentially, the applied voltage causes electrons and holes to recombine within the polymer layer, releasing energy in the form of light.

Polymer LED Advantages

Here are the advantages of Polymer LEDs:

• High Efficiency: They are very efficient, producing a good amount of light with low power consumption.
• Lightweight: As the name suggests, they are made from polymers, making them very light.
• Thin and Flexible: Their thin and flexible nature allows them to be used in various applications.
• High Temperature Range: They can operate in a wide range of temperatures.
• Large Viewing Angle: They offer a wide viewing angle for clear visibility.
• Shorter Response Time: They have a fast response time, allowing for quick switching.
• Smooth Brightness: They provide smooth and uniform brightness.
• Low Production Costs: Manufacturing costs are generally low.
• High Contrast: They offer high contrast for sharp images and text.
• Large Single Emitter and Arbitrary Structures: They can be fabricated as large single emitters and in arbitrary structures.

Polymer LED Disadvantages

The disadvantages of Polymer LEDs include:

• Sensitivity to Oxidation and Humidity: The emitter part is sensitive to oxidation and humidity, requiring careful encapsulation.
• Color Shift and Lifetimes: Different polymers can exhibit color shifts, and they have varying lifetimes.
• Short Lifetime at High Luminescence: Polymer LEDs tend to have a shorter lifespan when operated at high brightness levels.

Polymer LED Applications

Polymer LEDs are used in a variety of applications:

• Displays: They are used in displays for mobile phones, laptops, TVs, and advertising spaces.
• Lighting: They are widely used in the lighting industry for various applications.
• Automotive: They’re used in cars (e.g., bumpers).
• Wearable Technology: They’re used in vests, potentially including bulletproof vests.
• Electronic Newspapers: They’re used in the development of flexible electronic newspapers.

This Polymer LED tutorial provides a helpful overview for both beginners and advanced enthusiasts.