CdSe/CdS Çekirdek/Kabuk Kolloidal Nanolevhacıklar için Hibrit Ligand Mühendisliği

Öz

Kolloidal yarıiletken nanolevhacıklar (NPL’ler), dar ışıma bant aralıkları, baskılanmış Auger birleşimi ve yönelimli ışıma özellikleri sayesinde optoelektronik uygulamalar için oldukça cazip malzemelerdir. Ancak, sentez sırasında yaygın olarak kullanılan uzun zincirli organik ligandlar, yalıtkan bariyer olarak davranarak yük taşınımını sınırlar ve aygıt performansını olumsuz etkiler. Bu çalışmada, CdSe/CdS çekirdek/kabuk NPL’ler için inorganik metal halojenür pasivasyonu ile organik alkil amin ligandlarını birleştiren hibrit bir ligand stratejisi geliştirilmiştir. Çözelti içinde gerçekleştirilen ligand değişimi, farklı metal halojenür tuzları kullanılarak başlangıçtaki oleik asit ligandlarının etkin bir şekilde uzaklaştırılmasını sağlarken, NPL’lerin optik ve yapısal bütünlüğü korunmuştur. İncelenen ligandlar arasında, (NH4)2ZnCl4 en etkili inorganik pasivasyonu sağlayarak halojenür ile muamele edilmiş örnekler arasında en yüksek ışıma verimliliğine (%15) ulaşmıştır. Ardından uygulanan alkil amin işlemi, apolar çözücülerde kolloidal kararlılığı yeniden kazandırmış ve ışıma verimliliğinin sentez sonrası oleik asit ligandlar ile kaplı NPL’lerin değerlerine yaklaşacak şekilde önemli ölçüde artmasını sağlamıştır (%60). Bu hibrit ligand yaklaşımı, kolloidal NPL sistemlerinde kompakt yüzey pasivasyonu, yüksek ışıma verimliliği ve çözeltiyle işlenebilirliğin eş zamanlı olarak elde edilmesi için etkili bir yol sunmaktadır.

Anahtar Kelimeler

• Kolloidal yarıiletken nanokristaller
• Kolloidal nanolevhacıklar
• Ligand değişimi
• Optoelektronik malzemeler
• İnorganik ligandlar
• Nanomalzemeler

Hybrid Ligand Engineering for CdSe/CdS Core/Shell Colloidal Nanoplatelets

Öz

Colloidal semiconductor nanoplatelets (NPLs) are attractive materials for optoelectronic applications due to their narrow emission linewidths, suppressed Auger recombination and directional emission characteristics. However, the long-chain organic ligands commonly used during synthesis act as insulating barriers, limiting charge transport and compromising device performance. In this work, we develop a hybrid ligand strategy for CdSe/CdS core/shell NPLs that combines inorganic metal halide passivation with organic alkyl amine ligands. In-solution ligand exchange with various metal halide salts enables efficient removal of native oleic acid ligands while preserving the optical and structural integrity of the NPLs. Among the investigated ligands, (NH4)2ZnCl4 provides the most effective inorganic passivation, yielding the highest PLQY among halide-treated samples (15%). Subsequent alkyl amine treatment restores colloidal stability in nonpolar solvents and leads to a substantial recovery of PLQY (60%), approaching that of the as-synthesized NPLs. This hybrid ligand approach offers an effective route toward simultaneously achieving compact surface passivation, high optical efficiency, and solution processability in colloidal NPLs

Anahtar Kelimeler

• Colloidal semiconductor nanocrystals
• Colloidal nanoplatelets
• Ligand exchange
• Optoelectronic materials
• Inorganic ligands
• Nanomaterials

Kaynakça

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