en Research Paper Research Paper <p dir="ltr" style="text-align: justify"><font color="#000000"><span new="" style="font-family: " times="">In this paper, polycrystalline pure zinc oxide nano structured thin films were deposited on two kinds of single crystal and polycrystalline of p and n type Si in three different substrate temperatures of 300, 400 and 500^◦C by low cost APCVD method. Structural, electrical and optical properties of these thin films were characterized by X ray diffraction, two point probe method and </span><span new="" style="font-family: " times="">UV visible spectrophotometer respectively. IV measurements of these heterojunctions showed that turn on voltage and series resistance will increase with increasing substrate temperature in polycrystalline Si, while in single crystal Si, turn on voltage will decrease. </span><span new="" style="font-family: " times="">Although they are acceptable diodes, their efficiency as a heterojunction solar cell are so low</span></font></p> Heterojunction, Thin film silicon solar cell, Air pressure CVD, p-type Si, Diodes, ZnO 19 27 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-856-1&slc_lang=en&sid=1 M. Maleki masodeh.maleki@gmail.com 180031947532846003563 180031947532846003563 Yes Islamic Azad University,Branch of Fouman And Shaft M. Rozati smrozati@guilan.ac.ir 180031947532846003564 180031947532846003564 No Guilan university