Sains Malaysiana 43(10)(2014): 1557–1564

Simulation on the Roles of the Number of Quantum Well and Doping

in InxGa1-xN Multiple Quantum Wells LEDs

(Simulasi Peranan Bilangan Telaga Kuantum dan Pendopan dalam Multi Telaga Kuantum InxGa1-xN LEDs)

N. ZAINAL*, E. AZIMAH, Z. HASSAN, H. ABU HASSAN & M.R. HASHIM

Nano-optoelectronics Research and Technology, School of Physics, Universiti Sains Malaysia,

11800 Penang, Malaysia

Diserahkan: 2 Ogos 2013/Diterima: 10 Februari 2014

ABSTRACT

In this work, the emission efficiency of InxGa1-xN based light emitting diodes (LEDs) had been numerically investigated with the variation of the number of quantum well. From our calculation, we found that non-uniformity of carriers distribution (especially electron) in the wells leads to serious inhomogeneity of radiative recombination distribution that would degrade the efficiency of the LED with more wells. However, the problem was minimized when the selected quantum barriers were doped with a reasonable doping level. Comparison with other reported experimental works were also included. At the end of this work, we proposed several types of preferable LEDs designs with optimum structural parameters.

Keywords: Light emitting diodes; numerical simulation; optical properties; III-V semiconductors

ABSTRAK

Dalam kajian ini, kecekapan pancaran daripada diod pemancar cahaya (LED) berasaskan InxGa1-xN telah dikaji secara berangka dengan variasi bilangan telaga kuantum. Daripada pengiraan kami, didapati bahawa ketidakseragaman taburan pembawa (terutamanya elektron) dalam telaga memberi kesan kepada ketidakseragaman taburan penggabungan semula menyinar yang serius dan mengurangkan kecekapan LED yang mempunyai bilangan telaga yang tinggi. Walau bagaimanapun, kecekapan diod tersebut dapat diperbaiki apabila sawar kuantum tertentu didopkan pada tahap yang berpatutan. Perbandingan dengan kerja-kerja experimen lain yang telah dilaporkan turut disertakan. Di akhir kajian ini, kami mencadangkan beberapa jenis reka bentuk LED yang lebih baik dengan parameter struktur yang optimum.

Kata kunci: Diod pemancar cahaya; semikonduktor III-V; sifat optikal; simulasi berangka

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*Pengarang untuk surat-menyurat; email: norzaini@usm.my