CuInSe2 ve CuGaSe2 İnce Filmlerin Özellikleri Üzerine Karşılaştırmalı Çalışma

Öz

Cu(In_1-xGa_x)Se₂ (CIGS) yarıiletken ince filmlerin iki kenar noktası olan x=0 (CuInSe₂) ve x=1 (CuGaSe₂) ince filmleri, Cu, InSe ve GaSe hedeflerden saçtırma yöntemi ile 250 ^oC sıcaklıkta soda lime cam alttaşlar üzerine kaplandı. In ve Ga oranı ve üretim sonrası ısıl işlemin CuInSe₂ (CIS) ve CuGaSe₂ (CGS) ince filmlerin özellikleri üzerine etkileri araştırıldı. Üretilmiş filmlerin yapısal özelliklerini incelemek için  X-ışını kırınımı (XRD) ve örneklerin bileşenleri enerji dağılımlı X-ışını kırınımı analizi (EDXA) yöntemi kullanılarak analiz edildi. İnce film örneklerinin Raman aktif modlarının tayini için oda sıcaklığında Raman spektroskopi ölçümleri yapıldı. 400 ^oC sıcaklıkta ısıl işlem uygulanmış CIS ve CGS ince film örneklerinin en aktif modları (A₁ modu) en yoğun çizgilerin sırayla 178 cm^-1 ve 185 cm^-1 olduğu gözlendi. Bu mod kalkopirit yapıların Raman spektroskopisinde gözlemlenen en güçlü moddur. Isıl işlem uygulanmamış ve 350 ^oC’ta ısıl işlem uygulanmış CGS örneklerinde 486 cm^-1 çizgisi gözlenmiş olmasına rağmen bu çizginin yoğunluğu artan ısıl işlem sıcaklığı ile ters orantılı olarak azaldığı ve 400 ^oC uygulanan ısıl işlem sonrası tamamen yok olduğu gözlenmiştir. Üretilen CIS ve CGS ince filmlerin optik geçirgenlik ölçümleri sonucunda ısıl işlem uygulanmayan filmler ve at 400 ^oC sıcaklıkta ısıl işlem uygulanan filmler için optik bant aralıklarındaki değişim değerleri CIS için 1.28 eV ile  1.45 eV, CGS için 1.68 eV ile 1.75 eV aralıklarında değiştiği  hesaplandı. Numunelerin oda sıcaklığındaki elektriksel iletkenlikleri ısıl işlem öncesi ve 400 ^oC ısıl işlem sonrasında n-CIS için sırayla 8.6x10^-3 ve 13.6x10^-2 (Ω.cm)^-1, p-CGS için sırayla 1.6 and 1.9 (Ω.cm)^-1 olarak ölçüldü.

Anahtar Kelimeler

• CIS,CGS,İnce Filmler,Saçtırma,XRD,Raman Spektroskopisi

Comparative study on the properties of CuInSe2 and CuGaSe2 thin film

Öz

Two edge of Cu(In_1-xGa_x)Se₂ (CIGS) thin film semiconductors for x=0 (CuInSe₂) and x=1 (CuGaSe₂) have been produced onto the soda lime glass substrates at 250 ^oC by sputtering from Cu, InSe and GaSe targets. The effects of In and Ga ratio and the post-annealing at 350 ^oC and 400 ^oC on the properties of CuInSe₂ (CIS) and CuGaSe₂ (CGS) thin film samples have been investigated. The structural properties of the deposited films have been examined by using X-ray diffraction (XRD) and the compositions of samples were analyzed by performing energy dispersive X-ray diffraction analysis (EDXA) techniques. Raman spectra of thin film samples were studied at room temperature to determine the Raman active modes. The most intensive line (A₁ modes) at 178 cm^-1 and 185 cm^-1 were observed for CIS and CGS thin films annealed at 400 ^oC, respectively. This is the most active mode detected in the Raman spectra of this type of chalcopyrite structures. For as-grown and annealed CGS thin films at 350 ^oC , the line 486 cm^-1 was observed however intensity of this line decreased with increasing annealing temperature and totally disappeared after annealing at 400 ^oC. Optic transmission measurements showed that the deposited CIS and CGS thin films have optic band gap values for as grown and  annealed (at 400 ^oC)  samples changing from 1.28 eV  to 1.45 eV and from 1.68 eV to 1.75 eV respectively. The room temperature electrical conductivities of the samples were measured as 8.6x10^-3 and 13.6x10^-2 (Ω.cm)^-1 for n-type CIS thin film samples; 1.6 and 1.9 (Ω.cm)^-1 for p-type CGS thin film samples before and after annealing at 400 ^oC, respectively.

Anahtar Kelimeler

• CIS,CGS,Thin films,Sputtering,XRD,Raman Spectroscopy

Kaynakça

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