A New Source Of GaN-InGaN LED Performance Limitation?
Researchers point the finger at inherent background electron concentration
Scientists from Lakehead University and the epitaxy company MEAglow, both in Canada, have published a paper that highlights what they believe is a previously unidentified source of performance limitation in GaN-InGaN LED devices.
While most studies focus on output saturation known as 'current droop' from InGaN layer effects, the researchers show a similar influence from p-type GaN's inherent background electron concentration. The results were published online last week in the journal Solid-State Electronics.
They investigated p-GaN material to confirm that, even though the material had an excess of holes, the background electrons were indeed present and were influencing the charge flow across device electrodes. This current does not cross LED heterojunctions but rather drifts toward its proximal device electrode, causing a source of heating while providing no carriers for light emitting recombination.
The effects of this current were then explored in an LED configuration, whose output showed weak efficiency at very low biases in addition to that from current droop.
While the shortcoming under small currents has previously been attributed to electron tunneling across the junction, the researchers propose that another cause could be the background electrons inside p-GaN.
The full paper 'GaN-InGaN LED efficiency reduction from parasitic electron currents in p-GaN' by Greg Togtema, et al was published online last week in Solid-State Electronics Volume 103, January 2015.
AngelTech Live III: Join us on 12 April 2021!
AngelTech Live III will be broadcast on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST) and will feature online versions of the market-leading physical events: CS International and PIC International PLUS a brand new Silicon Semiconductor International Track!
Thanks to the great diversity of the semiconductor industry, we are always chasing new markets and developing a range of exciting technologies.
2021 is no different. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. We shall consider a roadmap for this device, along with technologies for boosting its output.
We shall also look at microLEDs, a display with many wonderful attributes, identifying processes for handling the mass transfer of tiny emitters that hold the key to commercialisation of this technology.
We shall also discuss electrification of transportation, underpinned by wide bandgap power electronics and supported by blue lasers that are ideal for processing copper.
Additional areas we will cover include the development of GaN ICs, to improve the reach of power electronics; the great strides that have been made with gallium oxide; and a look at new materials, such as cubic GaN and AlScN.
Having attracted 1500 delegates over the last 2 online summits, the 3rd event promises to be even bigger and better – with 3 interactive sessions over 1 day and will once again prove to be a key event across the semiconductor and photonic integrated circuits calendar.
So make sure you sign up today and discover the latest cutting edge developments across the compound semiconductor and integrated photonics value chain.
REGISTER FOR FREE