Materials and Technologies for Displays
Objectives
At the end of this course the students should have solid knowledge on the materials, structure, fabrication and operation of different flat panel displays, with special relevance on LCDs and OLEDs for the high-end market and electrophoretics and electrochromics for the low-end, which are the dominant technologies of the actual and upcoming market, as well as the different adressing schemes and technologies for these displays.
General characterization
Code
12607
Credits
6.0
Responsible teacher
Pedro Miguel Cândido Barquinha
Hours
Weekly - 4
Total - 76
Teaching language
Português
Prerequisites
Although not mandatory, it is advisable that the student completed Materiais Semicondutores, Microelectrónica II and Electrónica I.
Bibliography
Available soon
Teaching method
The program is divided in theoretical and lab classes, 2 and 3 hours per week, respectively.
Lectures are supported by ppts with updated and detailed information, which are then given to the students. Several practical examples are presented, having always in mind to discuss the viability of implementation of the materials and processes at an industrial scale.
The lab classes aim to fabricate different types of displays with different degrees of complexity, trying to show the students the different issues found during the fabrication process and how they affect the operation of the final display. Students also analyze commercial displays, evaluating how the different layers are assembled and what is their role, in order to understand the operation of the displays. Due to COVID19 lab classes were replaed by videos ilustrating LCD production.
The students are evaluated with two tests or alternatively a final exam (60 % of final mark), a group report about emerging display technologies an its presentation (25 %) and by a group lab questionnaire and an individual mask design for prodution of LCDs as ilustrated in the lab videos (15 %).
Evaluation method
The students are evaluated with two tests or alternatively a final exam (60 % of final mark), a group report about emerging display technologies an its presentation (25 %) and by a group lab questionnaire and an individual mask design for prodution of LCDs as ilustrated in the lab videos (15 %).
Subject matter
T:
- Introduction to displays: basic concepts, historical background, importance, applications and market, classification and main characterization parameters
- Fundaments of light, optics and visual perception
- Substrates for displays: properties, advantages and limitations of rigid and flexible substrates. The problematic of indium in displays
- Liquid crystal displays: introduction to liquid crystals (definitions, types, phases, properties), polarization and birefringence, the TN cell, addressing schemes (direct, passive and active matrices)
- Active Matrix LCDs: requirements, comparison of the different TFT technologies, other devices for on/off switching in AMLCDs. Optimization of AMLCDs: brightness, contrast, viewing angle, response time; flicker, image artifacts, power consumption
- Electroluminescent displays: OLEDs, TFELs and (micro)LEDs. QDs
- Main technologies of touch-screens
- 3D displays
- Active matrices for X-ray imaging panels
P:
Given the lab usage restrictions, some of the foreseen lab classes were replaced by videos (see detailed program in lecture 1). The pratical classes include:
- Production and characterization of LCD with segmented addressing and passive matrix
- Lab analysis of commercial OLED and LCD displays
- Assembly and driving of flexible EPD
- Exercises