Continuous-Flow Synthesis and Materials Interface Engineering of Lead Sulfide Quantum Dots for Photovoltaic Applications

الموضوعات

علوم تطبيقية وتكنولوجية

الملخص

Harnessing the Sun’s energy via the conversion of solar photons to electricity has emerged as a sustainable energy source to fulfill our future demands. In this regard, solution-processable, size-tunable PbS quantum dots (QDs) have been identified as a promising active materials for photovoltaics (PVs). Yet, there are still serious challenges that hinder the full exploitation of QD materials in PVs. This dissertation addresses two main challenges to aid these QDs in fulfilling their tremendous potential in PV applications.First, it is essential to establish a large-scale synthetic technique which maintains control over the reaction parameters to yield QDs with well-defined shape, size, and composition. Rigorous protocols for cost-effective production on a scale are still missing from literature. Particularly, previous reports of record-performance QD-PVs have been based on small-scale, manual, batch syntheses. One way to achieve a controlled large-scale synthesis is by reducing the reaction volume to ensure uniformity. Accordingly, we design a droplet-based continuous-flow synthesis of PbS QDs. Only upon separating the nucleation and growth phases, via a dual-temperature-stage reactor, it was possible to achieve high-quality QDs with high photoluminescence quantum yield (50%) in large-scale. The performance of these QDs in a PV device was comparable to batch-synthesized QDs, thus providing a promise in utilizing automated synthesis of QDs for PV applications.Second, it is crucial to study and control the charge transfer (CT) dynamics at QD interfaces in order to optimize their PV performance. Yet, the CT investigations based on PbS QDs are limited in literature. Here, we investigate the CT and charge separation (CS) at size-tunable PbS QDs and organic acceptor interfaces using a combination of femtosecond broadband transient spectroscopic techniques and steady-state measurements. The results reveal that the energy band alignment, tuned by the quantum confinement, is a key element for efficient CT and CS processes. Additionally, the presence of interfacial electrostatic interaction between the QDs and the acceptors facilitates CT from large PbS QD (bandgap < 1 eV); thus enabling light-harvesting from the broad near-infrared solar spectrum range.The advances in this work – from automated synthesis to charge transfer studies – pave new pathways towards energy harvesting from solution-processed nanomaterials.

روابط وملفات

التعريف والنوع

رقم الوثيقة

ee8ff2d9-4110-4712-8c6d-bf9f39b38e3b

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل دكتوراة

نوع الملف

pdf text

أسماء الملفات

1699805_1.pdf, 1699805_2.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":"Ala’a O. El-Ballouli","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"Osman Bakr","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

English

المصدر والدورية

اسم المصدر

Continuous-Flow Synthesis and Materials Interface Engineering of Lead Sulfide Quantum Dots for Photovoltaic Applications

المحتوى والصفحات

عدد الصفحات

0

كلمات الباحثين

Flow Reactor Synthesis , Interfacial Charge Transfer , Interfacial Electrostatic Interaction , Photovoltaics, Quantum Dots , time-resolved Spectroscopy

إشراف وإعداد

الإشراف

Osman Bakr

الإعداد

Ala’a O. El-Ballouli

الاقتباسات الببليوغرافية