Elsevier

Microelectronics Journal

Volume 38, Issues 6–7, June–July 2007, Pages 767-770
Microelectronics Journal

Effect of Si doping on the photoluminescence properties of AlGaInP/GaInP multiple quantum wells

https://doi.org/10.1016/j.mejo.2007.04.009Get rights and content

Abstract

The influence of Si doping on the photoluminescence (PL) properties of (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P multiple-quantum-wells (MQWs) was studied. For the samples without p-type layers, the PL peak wavelength from (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P MQWs did not vary when Si was doped in MQWs, the PL peak intensity did not change obviously and the PL FWHM broadened. We consider that Si doping results in worse interface quality of (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P MQWs. However, for the full light-emitting diode (LED) structure samples, the PL intensity of MQWs obviously increased when Si was doped in MQWs. The PL intensity from MQWs with Si-doped barriers was about 13 times stronger than that of undoped MQWs. The PL intensity from MQWs with Si-doped barriers and wells was strong as 28 times as that of undoped MQWs. The reasons are discussed.

Introduction

Significant advances in the light output performance of visible light-emitting diodes (LEDs) and light-emitting lasers (LDs) have been demonstrated using the AlGaInP alloy system [1], [2], [3], [4], [5], [6]. When grown lattice-matched to a GaAs substrate, the (AlxGa1−x)0.5In0.5P alloy has a direct band gap of about 1.8–2.3 eV (about 680–540 nm) as the aluminum composition x is changed from 0 to 0.7. This property makes AlGaInP an excellent material for efficient LEDs with a wide color range.

High-brightness AlGaInP LED usually uses a double heterostructure or a multi-quantum-wells (MQWs) active region. The active region needed to be undoped in order to reduce the nonradiative recombination centers [1], [2], [3], [4], [5]. However, the condition of III-nitride compounds is quite different [7], [8], [9], [10], [11], [12], [13], [14], [15]. The photoluminescence (PL) intensity from Si-doped InGaN layers was approximately one order of magnitude stronger than that from the undoped layers [7], [8]. The PL intensity of InGaN:Si/GaN:Si MQWs was obviously higher than that of undoped MQW sstructures [9], and the electron mobility was significantly increased [10]. The PL intensity of MQWs with Si-doped barriers was approximately 2500 times stronger than that of undoped MQWs [11], and the interface quality could be improved [12]. Furthermore, we notice that almost all of the successful InGaN laser structures have wells and barriers doped with Si or at least Si-doped barriers [13], [14], [15], [16]. In this paper, we report the Si doping effects on the properties of (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P MQWs.

Section snippets

Experimental details

The samples examined in this study were grown by EMCORE GS/3200 LP-MOCVD. Si-doped GaAs substrates were cut 15 degree off the (1 0 0) plane towards the [0 1 1] direction. The source materials were TMGa, TMIn, TMAl, AsH3, and PH3. CP2Mg and SiH4 were used for p- and n-type doping reagents. The growth temperatures were generally between 620 and 720 °C. Two types of samples were investigated. The first type of samples was grown (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P MQWs without p-type layers above it. The

Experimental results and discussion

Fig. 3 shows the room temperature PL spectra of samples a, b, and c. The characteristics of PL are listed in Table 1. It can be seen that just one peak appears from each sample, and the peak wavelengths of three samples are all at 641 nm. It means that the peak energy of MQWs does not vary with Si doping. The normalized intensities of samples a, b, and c are 1.0, 0.92, 0.95, respectively. It indicated that the peak intensity of MQWs do not change obviously with Si doping. This phenomenon is

Conclusions

In summary, the influence of Si doping on the photoluminescence (PL) properties of MQWs was studied. For the samples just only grown (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P MQWs, the PL peak wavelength from (Al0.3Ga0.7)In0.5P/Ga0.5In0.5P MQWs did not vary when Si is doped in MQWs, And the PL peak intensity did not change obviously and the PL FWHM broadened. We considered that the Si doping results in worse interface quality of (Al0.3Ga0.7)0.5In0.5P/Ga0.5In0.5P MQWs. However, for the samples with full

Acknowledgments

This work was supported by the National Nature Science Foundation of China (Grant no. 50602018), the Nature Science Foundation of Guangdong province (Grant no. 06025083), and the Science and Technology Program of Guangdong province (Grant no. 2006A10802001).

References (19)

  • C.-Y. Lee et al.

    J. Cryst. Growth

    (1999)
  • J.-R. Dong et al.

    J. Cryst. Growth

    (2004)
  • Y. Yamada et al.

    J. Cryst. Growth

    (1998)
  • Y.Z. Tong et al.

    Solid State Commun.

    (1999)
  • K.H. Huang et al.

    Appl. Phys. Lett.

    (1992)
  • F.A. Kish et al.

    Appl. Phys. Lett.

    (1994)
  • H. Sugawara et al.

    Jpn. J. Appl. Phys. Part 2

    (1995)
  • W.C. Peng et al.

    Appl. Phys. Lett.

    (2004)
  • S. Keller et al.

    Jpn. J. Appl. Phys. Part 2

    (1998)
There are more references available in the full text version of this article.

Cited by (0)

View full text