CdTe nanomalzeme ile güneş hücresi üretimi ve karakterizasyonu
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Dosyalar
Tarih
2018
Yazarlar
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Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Dünya genelinde enerjiye duyulan ihtiyacın artması buna karşın fosil yakıtların hızla azalması alternatif enerji kaynaklarının önemini artırmaktadır. Mevcut silisyum, germanyum bazlı birinci nesil güneş hücrelerinin yüksek maliyeti ve alternatif olarak ortaya çıkan ikinci nesil güneş hücrelerinin enerji dönüşüm verimlerinin %13 civarında kalması üçüncü nesil güneş hücreleri üzerine yoğunlaşma gereğini ortaya çıkarmıştır. Öyle ki henüz gelişim aşamasında olan üçüncü nesil güneş panelleri verim olarak birinci nesil güneş panellerini şimdiden yakalamışlardır. Üçüncü nesil güneş panelleri içinde Kuantum Nokta Duyarlı Güneş hücreleri (KNDGH) son beş yılda sergiledikleri aşama ile dikkat çekmektedir. Kolay işlenebilirlikleri, ayarlanabilir boyut ve bant aralıkları ve Çoklu Eksiton Üretimi (MEG) gibi benzersiz opto-elektronik özellikleri kuantum noktaları ilgi çekici hale getirmektedir. Bu özellikler KNDGH için teorik olarak enerji dönüşüm veriminin %44'e kadar çıkabileceğini göstermektedir. Bu çalışmada CdTe KNDGH tasarımı üzerine odaklanılmıştır. Tez çalışması 3 temel bölüme ayrılmıştır; CdTe KN sentezlenmesi, CdTe KN'nın tedavi edilmesi ve sentezlenen CdTe KN'lar ile KNDGH tasarlanması. CdTe KN sentezlenmesi için sıcak enjeksiyon metodu kullanılmış olup klasik metot ile sentezlenen CdTe KN Fotolümünesans Kuantum Verimi (PLQY) %8,12 olarak bulunmuştur. Sıcak enjeksiyon metodu daha sonra Kanula metoduyla modifiye edilmiş ve sentezlenen CdTe KN'nın PLQY değeri %25,66 ya çıkarılmıştır. Ayrıca KN'nın PL Maksimum Pik Noktasının Yarı Noktası (FWHM) 27nm seviyesine indirilmiş olup literatürdeki en yüksek monodispersi özelliği sergileyen organometalik CdTe KN sentezlenmiştir. Daha sonra sentezlenen CdTe KN'ya klorür pasifikasyon işlemi uygulanmış, farklı miktarda klorür (12-96 CdCI2/nm2) iyonu KN'ya enjekte edilmiştir. Yapılan analizler sonucunda 60 CdCI2/nm2 tedavisiyle CdTe(CI) KN'nın PLQY değeri %87,33'e çıkarılmıştır. Yapılan pasifleştirme tedavisi Kanula metoduyla %70 tekrarlanabilir hale getirilmiştir. Ayrıca CdTe KN'nın oksijen ortamında dayanım süresi 3 kat arttırılmıştır. Sentezleme ve tedavi işlemlerin ardından KNDGH tasarım aşamasına geçilmiştir. Bu aşamada KN'nın boyutu, TiO2 kalınlığı, FTO/TiO2 yüzeyine yapılan tedavi, CdTe KN'nın yüzeye tutturulması, redoks çifti ve toplayıcı elektrot seçimi üzerine birçok iyileştirme çalışması yapılmıştır. Tüm optimizasyon işlemleri sonucunda FTO/TiCI4/TiO2 (22µm) /TiCI4 /36 CdCI2/nm2 CdTe(CI) KN yüzey foto anot olarak kullanılırken, FTO/Pt yüzeyin toplayıcı elektrot olarak seçilmiştir. Bu iki yüzey arasına I-/I3- redoks çifti enjekte edilmiştir. Tasarlanan KNDGH için Jsc 3,22 mA/cm2, Voc 0,821V olurken, dolum faktörü %57,192 ve verim %1,515 olarak bulunmuştur. Bu verim değeri literatürdeki organometalik CdTe kullanılarak elde edilen en verimli (%0,197) CdTe KNDGH verimine göre 7,97 kat daha iyidir.
The increasing need for energy throughout the world, while the rapid reduction of fossil fuels, increases the importance of alternative energy sources. The high cost of the existing silicon and germanium based first generation solar panels, and the fact that the energy generation efficiency of the second generation solar panels, which are available as an alternative, is around 13%, has led to the need to concentrate on third generation solar panels. The third-generation solar panels, which are still in development stage, have already caught the first-generation solar panels in efficiency. Within the third generation solar panels, the Quantum Dot Sensitized Solar Cell (QDSSC) has attracted attention in the past five years. Unique opto-electronic features such as easy machinability, adjustable size and band gap, and Multiple Exciton Generation (MEG) make quantum dots attractive. These characteristics demonstrate that theoretically the energy conversion efficiency for QDSSC can be up to 44%. This work focuses on CdTe QDSSC design. Thesis is divided into 3 basic divisions; Synthesis of CdTe QD, treatment of CdTe QD and design of QDSSC with synthesized CdTe QDs. The hot injection method was used for synthesis of CdTe QD. Photoluminescence Quantum Yield (PLQY) of CdTe QDs, synthesized by the conventional method, was found to be 8.12%. The hot injection method was then modified by the Cannula method and the PLQY value was increased to 25.66%. Furthermore, Full Width Half Maximum (FWHM) of PL pik of CdTe QD was reduced to 27 nm so that the organometallic CdTe QD, which exhibited the highest monodispersity in the literature, was synthesized. Then, the synthesized CdTe QD was subjected to chloride passivation and different amounts of chloride (12-96 CdCl2/nm2) ions were injected into the QD. As a result of the analysis, it was determined that the PLQY value increased to 87.33% with 60 CdCl2/nm2 treatment. The passivization treatment was made 70% reproducible by Cannula method. Furthermore, the duration of the CdTe QD in the oxygen environment has been increased 3 times. After synthesis and treatment, QDSSC design studies were started. At this stage, several healing studies have been performed on CdTe QD size, TiO2 thickness, treatment on FTO / TiO2 surface, attachment of CdTe KN to the surface, redox couple and collecting electrode. As a result of all the optimization processes, FTO/TiCI4/TiO2 (22µm) /TiCI4/36 CdCI2/nm2 CdTe(CI) QD surface was used as photo anode and FTO/Pt surface was used as collecting electrode. I-/I3- redox couple was injected between these two surfaces. For the designed QDSSC, Jsc is 3.223mA/cm2, Voc is 0.821V, filling factor is 57.192% and efficiency is 1.51%. This efficiency is 7.97 times bigger than the similarities work (%0,197) in the literature.
The increasing need for energy throughout the world, while the rapid reduction of fossil fuels, increases the importance of alternative energy sources. The high cost of the existing silicon and germanium based first generation solar panels, and the fact that the energy generation efficiency of the second generation solar panels, which are available as an alternative, is around 13%, has led to the need to concentrate on third generation solar panels. The third-generation solar panels, which are still in development stage, have already caught the first-generation solar panels in efficiency. Within the third generation solar panels, the Quantum Dot Sensitized Solar Cell (QDSSC) has attracted attention in the past five years. Unique opto-electronic features such as easy machinability, adjustable size and band gap, and Multiple Exciton Generation (MEG) make quantum dots attractive. These characteristics demonstrate that theoretically the energy conversion efficiency for QDSSC can be up to 44%. This work focuses on CdTe QDSSC design. Thesis is divided into 3 basic divisions; Synthesis of CdTe QD, treatment of CdTe QD and design of QDSSC with synthesized CdTe QDs. The hot injection method was used for synthesis of CdTe QD. Photoluminescence Quantum Yield (PLQY) of CdTe QDs, synthesized by the conventional method, was found to be 8.12%. The hot injection method was then modified by the Cannula method and the PLQY value was increased to 25.66%. Furthermore, Full Width Half Maximum (FWHM) of PL pik of CdTe QD was reduced to 27 nm so that the organometallic CdTe QD, which exhibited the highest monodispersity in the literature, was synthesized. Then, the synthesized CdTe QD was subjected to chloride passivation and different amounts of chloride (12-96 CdCl2/nm2) ions were injected into the QD. As a result of the analysis, it was determined that the PLQY value increased to 87.33% with 60 CdCl2/nm2 treatment. The passivization treatment was made 70% reproducible by Cannula method. Furthermore, the duration of the CdTe QD in the oxygen environment has been increased 3 times. After synthesis and treatment, QDSSC design studies were started. At this stage, several healing studies have been performed on CdTe QD size, TiO2 thickness, treatment on FTO / TiO2 surface, attachment of CdTe KN to the surface, redox couple and collecting electrode. As a result of all the optimization processes, FTO/TiCI4/TiO2 (22µm) /TiCI4/36 CdCI2/nm2 CdTe(CI) QD surface was used as photo anode and FTO/Pt surface was used as collecting electrode. I-/I3- redox couple was injected between these two surfaces. For the designed QDSSC, Jsc is 3.223mA/cm2, Voc is 0.821V, filling factor is 57.192% and efficiency is 1.51%. This efficiency is 7.97 times bigger than the similarities work (%0,197) in the literature.
Açıklama
YÖK Tez No: 523075
Anahtar Kelimeler
Elektrik ve Elektronik Mühendisliği, Electrical and Electronics Engineering, Enerji, Energy, Enerji, Energy, Enerji verimliliği, Energy efficiency
