Pulsed laser deposition of ZnSe thin film on Si for heterojunction studies

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">ZnSe films were deposited on <i style="mso-bidi-font-style:normal">p</i>-Si and glass substrates by pulsed laser evaporation (PLE) and also by thermal evaporation (TE) at two substrate temperatures (<i style="mso-bidi-font-style:normal">T</i>_s) of 300 and 523 K. Films deposited on glass were amorphous at 300 K and polycrystalline zinc-blende at 523 K. X-ray photoelectron spectroscopy (XPS) studies showed that while both types of films deposited on Si were Zn rich, the PLE films had better stoichiometry for <i style="mso-bidi-font-style:normal">T</i>_s = 300 K and TE films for <i style="mso-bidi-font-style:normal">T</i>_s = 523 K. <i style="mso-bidi-font-style:normal">n</i>-ZnSe/<i style="mso-bidi-font-style: normal">p</i>-Si heterojunctions fabricated by PLE and TE were characterized by current voltage (<i style="mso-bidi-font-style:normal">I-V</i>) and capacitance-voltage (<i style="mso-bidi-font-style:normal">C- V</i>) techniques from which the ideality factor <i style="mso-bidi-font-style:normal">n</i>, reverse saturation current density <i style="mso-bidi-font-style:normal">J</i>_o and relative dielectric constants ϵ_r were determined. These measurements showed that films with better stoichiometry resulted in heterojunction with lower <i style="mso-bidi-font-style:normal">n</i> and <i style="mso-bidi-font-style: normal">J</i>_o.</span>