Investigation of Electrical Properties of GaSe:Ge/Te and GaSe:Ge/Ag Schottky Junctions

Öz

In this paper, we have investigated electrical properties of germanium doped Gallium Selenide (GaSe) single crystals. Germanium doped GaSe single crystals were grown by conventional Bridgman method. Shchottky junctions were obtained by melting Te or Ag elements on the GaSe:Ge surface. In contacts have been made for the electrical measurements. Characteristic properties of Schottky junctions were investigated as functions of temperature and electric field. It was observed that the ratio of forward bias and reverse bias currents in the Schottky junctions varied with both applied electric field and light excitations. Schottky junctions showed asymmetric current-voltage (I-V) characteristics. The light sensitivity of In/GaSe:Ge/Ag/In Schottky junction was found to be higher than that of In/GaSe:Ge/Te/In Schottky junction. The barrier heights of In/GaSe:Ge/Te/In and In/GaSe:Ge/Ag/In Schottky junctions were calculated as 52.92 meV and 41.82 meV, respevtively. Barrier heights of both Schottky junctions decreased with applied electric field. It was found that barrier heights of the Schottky junctions decreased with the square root of the applied electric field as  while the current increased exponentially with the square root of the applied electric field as . These results are consistent with the Frenkel thermoelectric field theory.

Anahtar Kelimeler

• Barrier height,gallium selenide,schottky junctions.

GASE:GE/TE VE GASE:GE/AG SCHOTTKY EKLEMLERİNİN ELEKTRİKSEL ÖZELLİKLERİNİN ARAŞTIRILMASI

Öz

Bu çalışmada, germanyum katkılı Galyum Selenit (GaSe) tek kristallerinin elektriksel özellikleri araştırıldı. Germanyum katkılı GaSe tek kristalleri geleneksel Bridgman metodu ile büyütüldü. Schottky eklemleri GaSe:Ge yüzeyleri üzerine Te ve Ag elementleri eritilerek elde edildi. Elektrik ölçümleri için indiyum kontaklar yapıldı. Schottky eklemlerinin karakteristik özellikleri elektrik alan ve sıcaklığın fonksiyonuna bağlı olarak araştırıldı. Elde edilen Schottky eklemlerinde düz yöndeki akımın ters yöndeki akıma oranının uygulanan elektrik alan ve ışıkla uyarılmaya bağlı olarak değiştiği gözlemlendi. Schottky eklemleri asimetrik akım-gerilim (I-V) karakteristiği gösterdi. In/GaSe:Ge/Ag/In Schottky ekleminin ışık duyarlılığının In/GaSe:Ge/Te/In Schottky ekleminden daha yüksek olduğu bulundu. In/GaSe:Ge/Te/In ve In/GaSe:Ge/Ag/In Schottky eklemlerinin bariyer yükseklikleri sırasıyla 52.92 meV and 41.82 meV olarak hesaplandı. Her iki Schottky ekleminin de bariyer yüksekliği uygulanan elektrik alanla azaldı. Schottky eklemlerinin bariyer yükseklikleri uygulanan elektrik alanın karekökü ile orantılı olarak  gibi küçüldüğü ve akımın uygulanan elektrik alanın karekökü ile gibi üstel olarak değiştiği bulundu. Bu sonuçların Frenkel termoelektrik alan teorisi ile uyumlu olduğu görüldü.

Anahtar Kelimeler

• Bariyer yüksekliği,galyum selenit,schottky eklemleri.

Kaynakça

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