Geri Dön

CuInSe2: Electronic activities of grain boundaries and solar cell fabrication studies

Başlık çevirisi mevcut değil.

  1. Tez No: 402341
  2. Yazar: MEHMET ERAY ERKAN
  3. Danışmanlar: PROF. MICHAEL H. C. JIN
  4. Tez Türü: Doktora
  5. Konular: Enerji, Energy
  6. Anahtar Kelimeler: Belirtilmemiş.
  7. Yıl: 2012
  8. Dil: İngilizce
  9. Üniversite: The University of Texas at Arlington
  10. Enstitü: Yurtdışı Enstitü
  11. Ana Bilim Dalı: Belirtilmemiş.
  12. Bilim Dalı: Belirtilmemiş.
  13. Sayfa Sayısı: 182

Özet

Özet yok.

Özet (Çeviri)

This dissertation is composed of three studies related to chalcopyrite solar cells. The first study is on electronic activities of grain boundaries (GBs) in CuInSe2 (CIS). Despite being polycrystalline, chalcopyrite thin film solar cells have reached record power conversion efficiencies. This is against the classical understanding on the effect of GBs in semiconductor materials. Because GBs are expected to be recombination centers and barriers against the carrier flow, reducing the device efficiency. Therefore, a complete understanding on the electronic behavior of chalcopyrite GBs is missing. Moreover, the high efficiency chalcopyrite solar cells are grown with Na impurities which positively affect the performance of the solar cell, so-called sodium effect. Research on chalcopyrite GBs has been coupled with the effect of Na impurities, because Na has been found segregated at the GBs. The study presented in this dissertation was performed on GBs in a Na-free CIS. It is important to study the GBs in a Na-free chalcopyrite to avoid any uncontrolled effects of Na segregation at the GBs, for instance a possible Na-related secondary phase formation which would affect the conclusions drawn on the natural behavior of chalcopyrite GBs. In addition, it is known that Σ3 GBs in chalcopyrite solar cells are abundant; therefore, it is meaningful to investigate the differences between Σ3 and non- Σ3 GBs. For this purpose, Σ3, ~Σ3 and Σ9 GBs in a Bridgman-grown multicrystalline Na-free CIS wafer were identified by electron backscatter diffraction and their electronic properties were investigated by Kelvin probe force microscope and cathodoluminescence in scanning electron microscope. It is shown that the Σ3 GB is neutral and it does not behave as a recombination center, whereas once the geometry of a GB deviates from the Σ3 geometry, such as ~Σ3 and Σ9 GBs, the GB becomes charged and behaves as a recombination center. This result was concluded to be due to the increase in the amount of defects at the GB that introduce midgap states as the Σ value increases. Our results indicate that the surprising high performance seen in the polycrystalline chalcopyrite solar cells is possibly due to the abundance of electrically inactive Σ3 GBs in this material. To investigate the effect of Na on CIS GBs, projected work includes the characterization of Σ3 and non-Σ3 GBs in CIS wafers grown with increasing Na concentration. Consequently, it will be possible to answer the following questions on the impact of sodium-effect on GBs: Is there a certain Na concentration for Na to affect the GB electrical properties and how does it affect both Σ3 and non-Σ3 GBs? In the second study, the use of selenoamide instead of direct use of H2Se for atmospheric pressure selenization reaction is proposed and its feasibility is shown by fabricating CIS solar cells with up to 1.6% power conversion efficiency. In addition, observed In and Ga segregation towards the bottom of the CIS and CIGS thin films, respectively, are investigated through phase transformations occurring during the selenization and systematically designed annealing processes. The third study is on the effect of flow type on the growth kinetics of CdS thin films deposited by chemical bath deposition. CdS thin films are deposited on glass substrates under turbulent and laminar flow conditions only by changing the substrate's alignment with respect to the bottom of the beaker in unstirred bath. It is shown that the flow condition of the bath does not change the optical and structural properties of CdS; however, deposition under laminar flow is explained to be diffusion-limited, whereas it is feed-limited under turbulent flow.

Benzer Tezler

  1. Ab initio calculations on electronic and lattice dynamical properties of CuInSe2 and CuInS2

    CuInSe2 ve CuInS2'ün elektronik ve örgü dinamiği özellikleri üzerine ab initio hesaplamalar

    CİHAN PARLAK

    Yüksek Lisans

    İngilizce

    İngilizce

    2002

    Fizik ve Fizik MühendisliğiAbant İzzet Baysal Üniversitesi

    Fizik Ana Bilim Dalı

    Y.DOÇ.DR. RESUL ERYİĞİT

  2. In2Se3 yarıiletken materyallerin yeni bir metot olan ko-depozisyon metoduyla sentezi ve karakterizasyonu

    Synthesis and characterization of In2Se3 semiconductor materials with a new co-deposition method

    SIDDIK DEMİR

    Yüksek Lisans

    Türkçe

    Türkçe

    2010

    KimyaAtatürk Üniversitesi

    Kimya Ana Bilim Dalı

    PROF. DR. ÜMİT DEMİR

  3. İki-aşamalı büyütme tekniği ile hazırlanan CuInSe2 filmlerinin yapısal, optik ve Schottky diyot özellikleri

    Structural, optical and Schottky diode properties of CuInSe2 films prepared by a two-step growth technique

    YAVUZ ATASOY

    Yüksek Lisans

    Türkçe

    Türkçe

    2012

    Fizik ve Fizik MühendisliğiKaradeniz Teknik Üniversitesi

    Fizik Ana Bilim Dalı

    DOÇ. DR. EMİN BACAKSIZ

  4. The effects of post-annealing process on the physical properties of silver-indium-selenium ternary semiconductor thin films deposited by electron beam technique

    Üretim sonrası tavlama işleminin elektron demeti tekniğiyle büyütülen gümüş-indiyum-selenyum üçlü yarıiletken ince filmlerin fiziksel özelliklerine etkileri

    TAHİR ÇOLAKOĞLU

    Doktora

    İngilizce

    İngilizce

    2009

    Fizik ve Fizik MühendisliğiOrta Doğu Teknik Üniversitesi

    Fizik Ana Bilim Dalı

    PROF. DR. MEHMET PARLAK

  5. Investigation of structural, electrical and optical properties of Cu1-XAgXInSe2thin films as a function of x content

    Cu1-XAgXInSe2 ince filmlerinin yapısal, elektriksel ve optiksel özelliklerinin x içeriğinin bir fonksiyonu olarak incelenmesi

    HASAN HÜSEYİN GÜLLÜ

    Yüksek Lisans

    İngilizce

    İngilizce

    2010

    Fizik ve Fizik MühendisliğiOrta Doğu Teknik Üniversitesi

    Fizik Bölümü

    PROF. DR. MEHMET PARLAK