Düşük Tellür Katkılı CuInGaSe2 İnce Filmlerin Yapısal Özelliklerinin İncelenmesi

Bu çalışmada Cu(In,Ga)(Se1-yTey)2 ince filmleri, külçe formundaki yapının elektron demeti ile buharlaştırılıp yüksek sıcaklıkta tavlanması ile elde edildi. Örneklerin X-ışını kırınım desenleri (XRD), Raman spektrumları, yüzey görüntüleri ile atomik konsantrasyon ölçümleri alınarak katkısız ve düşük Te katkılı örneklerin yapısal özellikleri ayrıntılı olarak incelenerek karşılaştırıldı. XRD desenlerinde, katkısız CIGS ince filminde, Cu(In,Ga)Se2 ve CuIn3Se5 gibi bir faz ayrışımının ortaya çıktığı, Te katkısı ile beraber faz ayrışımının ortadan kalktığı görüldü. Örneklere ait A1 Raman modlarının deneysel değerleri, teorik bir yaklaşımla elde edilen değerler ile karşılaştırıldı. Yüzey fotoğrafları incelendiğinde, Te katkısı ile beraber film yüzeyinin daha düzgün (uniform) hale geldiği ve tanelerin mikron-altı boyutlarında oluştuğu görüldü. Benzer şekilde, yapıdaki kompozisyon profilinin iyileştiği (Ga miktarının arttığı) ve hedeflenen miktarda Te’ün neredeyse yapıya girdiği görüldü.

Anahtar Kelimeler:

Bakır, İndiyum, Galyum, Selenyum, Tellür, ince film, kalkopirit kristal yapısı, CIGST

Investigation of Structural Properties of Low Te Doped CuInGaSe2 Thin Films

In this study, Cu(In,Ga)(Se1-yTey)2 thin films were obtained by evaporation of the bulk form compound with electron beam followed by annealing at elevated temperature. The X-ray diffraction patterns (XRD), Raman spectra, surface images and atomic concentration measurements of the samples were analyzed and compared with the structural properties of the undoped and low Te doped samples. In XRD patterns, it was observed that a phase separation such as Cu(In,Ga)Se2 and CuIn3Se5 formed in the CIGS thin film, but with the Te content, this phase separation was disappeared. Experimental values of A1 Raman modes of the samples were compared with the values obtained by a theoretical approach. It was seen that the film surface became more uniform and the particles formed in sub-micron dimensions as the Te content increase in the film. Similarly, it was observed that the composition profile in the structure improved (the amount of Ga increased) and that the targeted amount of Te almost entered the structure.

Keywords:

Copper, Indium, Gallium, Selenide, Telluride, thin film, chalcopyrite crystal structure, CIGST,

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