Bond, But Not James Bond
LG Display (LPL) has announced a new, brighter OLED display, called OLED-EX, which it expects to put into production at its plants in Paju, South Korea during the 2nd quarter of 2022. The company is said to have been using the new material at its plant in Guangzhou, China as part of its OLED TV panel supply to parent LG Electronics (066570.KS) for its EVO OLED TV line. The changes to the new panel are said (by the company) to be two-fold, with the first part a change in material composition, and the second a change in the way the sub-pixels are used. LGD did not give much information on either change but we derive at least somewhat of an idea about the possible change to LGD’s OLED material composition.
Organic compounds are based on carbon, where the carbon atom is bonded to a hydrogen or other atoms or radical structures. The bonds between these two elements comes from the fact that carbon, which has 4 electrons in its outer shell can share those electrons with 4 hydrogen atoms that have 1 electron in their outer shell. In OLED displays, the application of an electrical current pushes the electrons out of the shell and as they fall back they give off that extra energy as light, hence the name light-emitting diodes; essentially what goes in as electrical energy comes out as light. Sounds simple but it’s not. If the reaction happens too quickly some of the excitons (let’s say ‘excited electron’) ‘quench’ the reaction of other excitons, reducing the light generated, and too little ‘push’ from applied current produces no reaction, so the organic materials and the electrical charge have to be carefully balanced.
Over time the bonds that hold such organic materials deteriorate, with higher energy organic materials (blue) deteriorating more quickly than lower energy materials (red and green), creating both lifetime discrepancies and persistence problems, also known as burn-in. Chemical engineers have found that by substituting an isotope of hydrogen called deuterium, which still has the same one electron to bond to carbon but is a bit heavier (aka ‘heavy hydrogen’), they can slow down the reaction and reduce the ‘quenching’, increasing the brightness of the material without the normal decrease in lifetime that comes with more typical methods of driving materials to higher brightness by increasing the current. While deuterium occurs naturally in water, the ratio is one atom for every 6,420 ‘regular’ hydrogen atoms and the process to separate those atoms is energy intensive, so LGD is buying the blue material from supplier DuPont (DOW), rather than its usual supplier of fluorescent blue emitter material, idemitsu Koasan (5019.JP).
While we don’t know precisely what LG Display has done to its OLED materials, based on IP filings by Samsung Display (pvt), Universal Display (OLED), LG Chem (051910.KS), Rohm & Haas (DOW) and others[1], the idea of substituting heavy hydrogen for elemental hydrogen in OLED materials is one of interest to many of those developing such materials, especially blue emitters and hosts, so we speculate a bit on what LG Display has done on the material side to generate a new OLED brand name. As to the results, which are said to boost brightness between 25% and 30%, we expect both the material change and a new AI pixel processor contribute to the increase.
[1] Jeong, Eunjae, et al. ORGANIC ELECTROLUMINESCENCE DEVICE AND AMINE COMPOUND FOR ORGANIC ELECTROLUMINESCENCE DEVICE.
Chen, Hsiao-Fan, and Jason Brooks. ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES.
Kim, Chi-Sik, et al. ORGANIC ELECTROLUMINESCENT COMPOUND AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME.
Kim, Seong-So, et al. ORGANIC LIGHT EMITTING DEVICE.
DOH, Yoo-Jin, et al. ORGANIC ELECTROLUMINESCENT DEVICE.
Organic compounds are based on carbon, where the carbon atom is bonded to a hydrogen or other atoms or radical structures. The bonds between these two elements comes from the fact that carbon, which has 4 electrons in its outer shell can share those electrons with 4 hydrogen atoms that have 1 electron in their outer shell. In OLED displays, the application of an electrical current pushes the electrons out of the shell and as they fall back they give off that extra energy as light, hence the name light-emitting diodes; essentially what goes in as electrical energy comes out as light. Sounds simple but it’s not. If the reaction happens too quickly some of the excitons (let’s say ‘excited electron’) ‘quench’ the reaction of other excitons, reducing the light generated, and too little ‘push’ from applied current produces no reaction, so the organic materials and the electrical charge have to be carefully balanced.
Over time the bonds that hold such organic materials deteriorate, with higher energy organic materials (blue) deteriorating more quickly than lower energy materials (red and green), creating both lifetime discrepancies and persistence problems, also known as burn-in. Chemical engineers have found that by substituting an isotope of hydrogen called deuterium, which still has the same one electron to bond to carbon but is a bit heavier (aka ‘heavy hydrogen’), they can slow down the reaction and reduce the ‘quenching’, increasing the brightness of the material without the normal decrease in lifetime that comes with more typical methods of driving materials to higher brightness by increasing the current. While deuterium occurs naturally in water, the ratio is one atom for every 6,420 ‘regular’ hydrogen atoms and the process to separate those atoms is energy intensive, so LGD is buying the blue material from supplier DuPont (DOW), rather than its usual supplier of fluorescent blue emitter material, idemitsu Koasan (5019.JP).
While we don’t know precisely what LG Display has done to its OLED materials, based on IP filings by Samsung Display (pvt), Universal Display (OLED), LG Chem (051910.KS), Rohm & Haas (DOW) and others[1], the idea of substituting heavy hydrogen for elemental hydrogen in OLED materials is one of interest to many of those developing such materials, especially blue emitters and hosts, so we speculate a bit on what LG Display has done on the material side to generate a new OLED brand name. As to the results, which are said to boost brightness between 25% and 30%, we expect both the material change and a new AI pixel processor contribute to the increase.
[1] Jeong, Eunjae, et al. ORGANIC ELECTROLUMINESCENCE DEVICE AND AMINE COMPOUND FOR ORGANIC ELECTROLUMINESCENCE DEVICE.
Chen, Hsiao-Fan, and Jason Brooks. ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES.
Kim, Chi-Sik, et al. ORGANIC ELECTROLUMINESCENT COMPOUND AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME.
Kim, Seong-So, et al. ORGANIC LIGHT EMITTING DEVICE.
DOH, Yoo-Jin, et al. ORGANIC ELECTROLUMINESCENT DEVICE.
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