Flexibility of p–n Junction Formation from SWIR to LWIR Using MBE-Grown Hg(1–x)Cd x Te on Si Substrates

Abstract

In this paper, we show the versatility of using molecular-beam epitaxy (MBE) for the growth of the mercury cadmium telluride (HgCdTe) system. Abrupt composition profiles, changes in doping levels or switching doping types are easily performed. It is shown that high-quality material is achieved with Hg (1-x) Cd x Te grown by MBE from a cadmium mole fraction of x = 0.15 to x = 0.72. Doping elements incorporation as low as 10 15 cm À3 for both n-type and p-type material as well as high incorporation levels >10 18 cm À3 for both carrier types were achieved. X-ray curves, secondary-ion mass spectrometry (SIMS) data, Hall data, the influence of doping incorporation with cadmium content and growth rate, etch pit density (EPD), composition uniformity determined from Fourier-transform infrared (FTIR) transmission spectroscopy, and surface defect maps from low to high x values are presented to illustrate the versatility and quality of HgCdTe material grown by MBE. All data presented in this work are from layers grown on silicon (112) substrate.

Microstructure of Heteroepitaxial ZnTe Grown by Molecular Beam Epitaxy on Si(211) Substrates

“…Acceptable crystal quality and electrical characteristics of HgCdTe grown on CdTe(211)B/Si(211) by molecular beam epitaxy (MBE) have been demonstrated. 1 Furthermore, MBE-grown CdTe on Si has proven to be a promising heterostructure for high-efficiency solar cells, which can greatly lower the cost per watt of singleand multijunction solar cells. 2 It is essential to grow ZnTe on As-passivated Si(211) substrates before deposition of CdTe to alleviate the significant lattice mismatch between CdTe and Si, maintain the (211) orientation for the subsequent CdTe growth, and ensure that the surface is terminated with Te (B surface).…”