Piezoelectric Effect of Perovskites

**Chapter 9**

**Abstract**

**1. Introduction**

**175**

Effect of Piezoelectric Filed on the

InAlAs alloy was grown by MOCVD on an InP (311) substrate with different polarities. Measurements of photoluminescence (PL) and photoreflectance (PR) were performed to study the impact of the V/III flux ratio. It is discovered that the PL line was shifted to a greater energy side with the increasing excitation power density, and no saturation was observed of its related PL intensity. It is a fingerprint of type II transition emission. However, the recombination of the type II interface showed a powerful dependence on AsH3 overpressure and substrate polarity. In fact, we have noted an opposite behavior of type II energy transition shift from A to B polarity substrate in respect to V/III ratio variation. PR signals corresponding to Franz-Keldysh Oscillation (FKO) were observed. The analysis of their period has allowed one to assess the value of the PZ field in the samples. PL-luminescence measurements were performed out as a function of temperature. PL peak energy, PL intensity, and half maximum full width show anomalous behaviors. Indicating the existence of localized carriers, they were ascribed to the energy potential modulation associated with the indium cluster formation and PZ field.

**Keywords:** V/III flux ratio, substrate polarity, piezoelectric field, Franz-Keldysh

Recently, scientists have focused their interest in InAlAs/InP grown on nonconventional (n11) planes. For example, (311) A and (311) B are not acquired as compared to the used (001) surface due to their remarkable characteristics [1]. In addition, InAlAs semiconductor layers grown on (311) A/B-oriented InP substrates give several unique characteristics compared to those grown on InP (100). Indeed, in (311) plane, the strain and hydrostatic deformations are discovered to be

improved compared to those on (100) plane [1–3]. The primary reasons for this are: (i) the presence of a built-in electric field, produced through the piezoelectric effect in the layer [1, 4, 5] and (ii) the difference in arsenic segregation at the inverse interface. It is expected that these factors will be heavily dependent on growth

InAlAs-InP materials have attracted tremendous interest over the past decades

due to a variety of potential applications such as optical, optoelectronic and

oscillation, photoreflectance, photoluminescence

conditions such as substrate orientation, V/III ratio.

Optical Properties of (311) A and

(311) B Oriented InAlAs/InP

*Badreddine Smiri, Faouzi Saidi and Hassen Maaref*

Heterostructures
