DOI: 10.1051/jp4:2006137046 The acoustic method of investigating the electrical carrier mobility of the real GaP:Te (110) surface∗

Abstract. The acoustic method of investigating the carrier mobility in the near-surface region of a semiconductor is presented. In this method the transverse acoustoelectric voltage versus the absorbed surface acoustic wave power was measured to determine nondestructively the carrier mobilites. In the layered structure: piezoelectric- semiconductor, the majority and minority carrier mobilities can be determined basing on the field effect. Single GaP:Te(110) crystals have been investigated after various kinds pf surface treatment. The carrier mobility values range from 75 to 120 (cm2 / V s). The results determined by means of the TAV method are in satisfactory agreement with the results obtained by Hall measurements. 1. EXPERIMENTAL During the past years, the high-frequency and nondestructive surface acoustic wave (SAW) measurement technique has been developed and used to characterise the electron and electrical surface properties of semiconductor materials. A surface acoustic wave in piezoelectric materials is accompanied by a decaying electric field which interacts with the free carriers of the semiconductor placed nearby. The reaches of effects which are results of this interaction is really great [1]. In the majority of these experiments, transverse acoustoelectric voltage (TAV) methods were used [2]. By the TAV methods can be determined such important surface semiconductor parameters as