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CdSe ve CdSe/ZnO Filmlerin Elektrokimyasal Sentezi: Morfolojik, Yapısal ve Elektronik Özellikler

CdSe filmler ITO elektrot üzerinde sabit potansiyel uygulayarak sulu çözeltide elektrokimyasal yolla hazırlanmıştır. CdSe ince filmlerin yapısal, morfolojik ve optik özellikleri FE-SEM, XRD ve UV-görünür spektrofotometri teknikleri çalışılmıştır. XRD sonuçları, CdSe filmlerin Na2SO4 destek elektroliti varlığında Cd2+ ve Se4+ içeren sulu çözeltiden kübik kristal formda biriktirildiği görülmüştür. CdSe filmlerin bant aralığı değerleri 1,88 ve 2,0 eV aralığında bulunmuştur. Geniş bant aralığına sahip ZnO dar bant aralığına sahip CdSe üzerine optoelektronik özelliklerini geliştirmek için elektrokimyasal yolla biriktirilmiştir. CdSe/ZnO nanoçubukların bant aralığı değeri 2,7 eV olarak belirlenmiştir. Mott-Schottky eşitliği malzemelerin düz bant potansiyelini (EFB) ve yük taşıyıcı yoğunluğunu (ND) hesaplamak için kullanılmıştır. ND değerleri, CdSe ve CdSe/ZnO için 1.623×1020 ve 9.186×1020 cm-3 olarak bulunmuştur. Daha yüksek kararlılık ve düşük bant aralığı sağlayan ZnO, güneş pili uygulamalarında kullanılmak için umut verici bir malzemedir.

Anahtar Kelimeler:

CdSe/ZnO, Yarıiletken malzemeler, Elektrokimyasal biriktirme

Electrochemical Synthesis of CdSe and CdSe/ZnO Films: Morphological, Structural and Electronic Properties

CdSe films were electrochemically prepared on ITO electrode in aqueous solution applying a constant potential. Structural, morphological and optical features of CdSe thin films were examined with FE-SEM, XRD and UV-visible spectrophotometry techniques. XRD results revealed CdSe films were deposited, in the form of cubic crystals from aqueous solution of Cd2+ and Se4+, in presence of Na2SO4 supporting electrolyte. Band gap values of CdSe films were found between 1.88 and 2.0 eV. Wide band gap ZnO was electrochemically deposited on narrow band gap CdSe to improve its optoelectronic properties. Band gap value of CdSe/ZnO nanonorods was determined as 2.7 eV. Mott-Schottky equation was utilized to calculate flat band potential (EFB), as well as charge carrier density (ND) of materials. ND values were found as 1.623×1020 and 9.186×1020 cm-3 for CdSe and CdSe/ZnO, respectively. ZnO offers higher stability and lower band gap is promising material to be utilized in solar cell applications.

Keywords:

CdSe/ZnO, Semiconductor materials, Electrochemical deposition,

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