Toward RGB LEDs based on rare earth-doped ZnO

Abstract

By using ZnO thin films doped with Ce, Tb or Eu, deposited via RF magnetron sputtering, we have developed monochromatic (blue, green and red, respectively) light emitting devices. The rare earth ions introduced with doping rates lower than 2% exhibit narrow and intense emission peaks due to electronic transitions in relaxation processes induced after electrical excitation. This study proves zinc oxide to be a good host for these elements; its high conductivity and optical transparency in the visible range being as well exploited as top transparent electrode. After structural characterization of the different doped layers, a device structure with intense electroluminescence is presented, modelled, and electrically and optically characterized. The different emission spectra obtained are compared in a chromatic diagram, providing a reference for future works with similar devices. The results hereby presented demonstrate three operating monochromatic light emitting devices, as well as a combination of the three species into another one, with a simply-designed structure compatible with current Si technology and demonstrating an integrated RGB emission.

Rare Earth Element Doped ZnO Thin Films and Applications

“…ZnO is preferred for use in many technological areas such as solar cells, light emitting diodes, gas sensors and flat panel displays due to its good optic and electrical properties, as well as its non-toxic, low cost, easy production (Anand et al, 2018a;Frieiro et al, 2020;Gottardi et al, 2013;Üzar, 2018). In addition, it is used in different applications such as blue luminescent devices, solar cell windows, laser diodes, optical sensors (Kayani et al, 2020).…”

“…Thin films have been found to be higly suitable for opto-electronic device applications (Anand et al, 2018a). Ce, Tb and Eu doped ZnO thin films were prepared by Frieiro et al, (2020) using RF magnetron sputtering and they developed monochromatic light emitting devices in blue for Ce, green for Tb and red for Eu (Frieiro et al, 2020). Luo et al (2012) investigated photoluminescence properties of undoped and Ce-doped ZnO films prepared by DC magnetron sputtering.…”

High Quality Inkjet Printed‐Emissive Nanocrystalline Perovskite CsPbBr3 Layers for Color Conversion Layer and LEDs Applications

“…[1][2][3] Among other drawbacks, organic light-emitting diodes (OLEDs) can degrade fast, especially blue-emitting OLEDs, and are fabricated with complex and expensive technologies which require advanced lithography and clean room environment. [4][5][6][7] In contrast, cost-effective solution processable methods not requiring lithography and based on MHPs have been recently used to produce large-area, highly efficient and low-cost optoelectronic devices and solar cells. [8] MHPs are especially wellsuited for solution processable methods because of their easy synthesis at low temperature, defect tolerance, high absorption capability, tunability of bandgap energy within the visible and near infrared ranges, high photoluminescence quantum yield (PLQY), narrow emission peak, good transport properties and a low density of non-radiative recombination centers.…”

“…[ 1–3 ] Among other drawbacks, organic light‐emitting diodes (OLEDs) can degrade fast, especially blue‐emitting OLEDs, and are fabricated with complex and expensive technologies which require advanced lithography and clean room environment. [ 4–7 ]…”

Pr3+ Katkılı ZnO Nanoparçacıkların Hidrotermal Yöntemle Sentezi ve Karakterizasyonu

“…Bu nedenle, Ln 3+ :Pr, Eu, Er,Yb…v.b. nadir toprak metali katkılı ZnO yarı iletken malzemeler üzerine yapılan araştırmalar son yıllarda hız kazanmıştır [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Düşük oranlarda Pr katkılanması bile, ZnO nanoyapıların, optoelektrik performansını, fotokatalitik aktivitesini, fotoelektrik ve lüminesans özelliklerini iyileştirebilmektedir [17][18][19].Özellikle Pr 3+ iyonu katkılanmasıyla ZnO tabanlı yarıiletken malzemelerin buharlaşma, faz saflığı oluşumu, tane büyümesi ve elektrik akımının etkin akışı gibi özelliklerindeki değişim etkileri kullanılarak Bi2O3 tabanlı ZnO varistörlerindeki dezavantajlar giderilmektedir [20][21][22].…”