scholarly journals Comparison of the heat-treatment effect on carrier dynamics in TiO2 thin films deposited by different methods

2021 ◽  
Author(s):  
Ramsha Khan ◽  
Harri Ali-Löytty ◽  
Antti Tukiainen ◽  
Nikolai V Tkachenko
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Titanium Dioxide ◽  
Charge Carrier ◽  
Carrier Lifetime ◽  
Carrier Dynamics ◽  
Fabrication Method ◽  
Tio2 Thin Films ◽  
Titanium Dioxide Thin Films ◽  
Charge Carrier Lifetime

Polycrystalline titanium dioxide thin films are routinely used in a broad range of applications where charge carrier lifetime is essential to the performance but the effects of fabrication method are...

scholarly journals Ultrafast Charge Carrier Dynamics in Vanadium-Modified TiO2 Thin Films and Its Relation to Their Photoelectrocatalytic Efficiency for Water Splitting

2020 ◽  
Vol 124 (49) ◽  
pp. 26572-26582
Author(s):  
Alberto Piccioni ◽  
Daniele Catone ◽  
Alessandra Paladini ◽  
Patrick O’Keeffe ◽  
Alex Boschi ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Carrier ◽  
Water Splitting ◽  
Carrier Dynamics ◽  
Tio2 Thin Films ◽  
Charge Carrier Dynamics

Charge carrier lifetime in boron carbide thin films

2011 ◽  
Vol 98 (19) ◽  
pp. 192106 ◽  
Author(s):  
Ruqiang Bao ◽  
Zijie Yan ◽  
Douglas B. Chrisey
Keyword(s):  
Thin Films ◽  
Charge Carrier ◽  
Boron Carbide ◽  
Carrier Lifetime ◽  
Charge Carrier Lifetime

scholarly journals An efficient PE-ALD process for TiO2 thin films employing a new Ti-precursor

2016 ◽  
Vol 4 (5) ◽  
pp. 1057-1065 ◽  
Author(s):  
M. Gebhard ◽  
F. Mitschker ◽  
M. Wiesing ◽  
I. Giner ◽  
B. Torun ◽  
...  
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Low Temperature ◽  
Tio2 Thin Films ◽  
Gas Barrier ◽  
Polymer Substrates ◽  
Barrier Layers ◽  
Titanium Dioxide Thin Films

A new Ti-precursor for low-temperature PE-ALD of titanium dioxide thin films as gas barrier layers on polymer substrates.

scholarly journals Long-lived charge carrier generation in ordered films of a covalent perylenediimide–diketopyrrolopyrrole–perylenediimide molecule

2015 ◽  
Vol 6 (1) ◽  
pp. 402-411 ◽  
Author(s):  
Patrick E. Hartnett ◽  
Scott M. Dyar ◽  
Eric A. Margulies ◽  
Leah E. Shoer ◽  
Andrew W. Cook ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Carrier ◽  
Carrier Lifetime ◽  
Building Blocks ◽  
Carrier Generation ◽  
Solvent Vapor ◽  
Vapor Annealing ◽  
Donor Acceptor ◽  
Solvent Vapor Annealing ◽  
Charge Carrier Lifetime

Self-ordering of covalent electron donor–acceptor building blocks in thin films upon solvent vapor annealing results in a 104 increase in photo-generated charge carrier lifetime.

scholarly journals Unravelling Defect Passivation Mechanisms in Sulfur-treated Sb2Se3

2021 ◽  
Author(s):  
Rajiv Ramanujam Prabhakar ◽  
Thomas Moehl ◽  
Dennis Friedrich ◽  
Marinus Kunst ◽  
Sudhanshu Shukla ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Lifetime ◽  
Low Frequency ◽  
Surface Region ◽  
Carrier Dynamics ◽  
Time Resolved ◽  
Charge Carrier Dynamics ◽  
Recombination Efficiency ◽  
Defect Passivation ◽  
Charge Carrier Lifetime

<p>Sb<sub>2</sub>Se<sub>3 </sub>has emerged as an important photoelectrochemical (PEC) and photovoltaic (PV) material due to its rapid rise in photoconversion efficiencies. However, despite its binary nature, Sb<sub>2</sub>Se<sub>3 </sub>has a complex defect chemistry, which reduces the maximum photovoltage that can be obtained. Thus, it is important to understand these defects and to develop passivation strategies in order to further improve this material. In this work, a comprehensive investigation of the charge carrier dynamics of Sb<sub>2</sub>Se<sub>3</sub> and the influence of sulfur treatment on its optoelectronic properties was performed using time resolved microwave conductivity (TRMC), photoluminescence (PL) spectroscopy and low frequency Raman spectroscopy (LFRS). The key finding in this work is that upon sulfur treatment of Sb<sub>2</sub>Se<sub>3</sub>, the carrier lifetime is increased by the passivation of deep defects in Sb<sub>2</sub>Se<sub>3</sub> in both the surface region and the bulk, which is evidenced by increased charge carrier lifetime of TRMC decay dynamics, increased radiative recombination efficiency and decreased deep defect level emission (PL), and improved long-range order in the material (LFRS). These findings provide crucial insights into the defect passivation mechanisms in Sb<sub>2</sub>Se<sub>3</sub> paving the way for developing highly efficient PEC and PV devices.</p>

scholarly journals Unravelling Defect Passivation Mechanisms in Sulfur-treated Sb2Se3

2021 ◽  
Author(s):  
Rajiv Ramanujam Prabhakar ◽  
Thomas Moehl ◽  
Dennis Friedrich ◽  
Marinus Kunst ◽  
Sudhanshu Shukla ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Lifetime ◽  
Low Frequency ◽  
Surface Region ◽  
Carrier Dynamics ◽  
Time Resolved ◽  
Charge Carrier Dynamics ◽  
Recombination Efficiency ◽  
Defect Passivation ◽  
Charge Carrier Lifetime

<p>Sb<sub>2</sub>Se<sub>3 </sub>has emerged as an important photoelectrochemical (PEC) and photovoltaic (PV) material due to its rapid rise in photoconversion efficiencies. However, despite its binary nature, Sb<sub>2</sub>Se<sub>3 </sub>has a complex defect chemistry, which reduces the maximum photovoltage that can be obtained. Thus, it is important to understand these defects and to develop passivation strategies in order to further improve this material. In this work, a comprehensive investigation of the charge carrier dynamics of Sb<sub>2</sub>Se<sub>3</sub> and the influence of sulfur treatment on its optoelectronic properties was performed using time resolved microwave conductivity (TRMC), photoluminescence (PL) spectroscopy and low frequency Raman spectroscopy (LFRS). The key finding in this work is that upon sulfur treatment of Sb<sub>2</sub>Se<sub>3</sub>, the carrier lifetime is increased by the passivation of deep defects in Sb<sub>2</sub>Se<sub>3</sub> in both the surface region and the bulk, which is evidenced by increased charge carrier lifetime of TRMC decay dynamics, increased radiative recombination efficiency and decreased deep defect level emission (PL), and improved long-range order in the material (LFRS). These findings provide crucial insights into the defect passivation mechanisms in Sb<sub>2</sub>Se<sub>3</sub> paving the way for developing highly efficient PEC and PV devices.</p>

scholarly journals Optimization of Photogenerated Charge Carrier Lifetimes in ALD Grown TiO2 for Photonic Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1567
Author(s):  
Ramsha Khan ◽  
Harri Ali-Löytty ◽  
Jesse Saari ◽  
Mika Valden ◽  
Antti Tukiainen ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Carrier Lifetime ◽  
Transient Absorption ◽  
Anatase Phase ◽  
Atomic Layer ◽  
Transient Absorption Spectroscopy ◽  
High Temperature Treatment ◽  
Tio2 Thin Films ◽  
Long Lifetime

Titanium dioxide (TiO2) thin films are widely employed for photocatalytic and photovoltaic applications where the long lifetime of charge carriers is a paramount requirement for the device efficiency. To ensure the long lifetime, a high temperature treatment is used which restricts the applicability of TiO2 in devices incorporating organic or polymer components. In this study, we exploited low temperature (100–150 °C) atomic layer deposition (ALD) of 30 nm TiO2 thin films from tetrakis(dimethylamido)titanium. The deposition was followed by a heat treatment in air to find the minimum temperature requirements for the film fabrication without compromising the carrier lifetime. Femto-to nanosecond transient absorption spectroscopy was used to determine the lifetimes, and grazing incidence X-ray diffraction was employed for structural analysis. The optimal result was obtained for the TiO2 thin films grown at 150 °C and heat-treated at as low as 300 °C. The deposited thin films were amorphous and crystallized into anatase phase upon heat treatment at 300–500 °C. The average carrier lifetime for amorphous TiO2 is few picoseconds but increases to >400 ps upon crystallization at 500 °C. The samples deposited at 100 °C were also crystallized as anatase but the carrier lifetime was <100 ps.

Surface Morphology and Structure Study of Titanium Dioxide Thin Films Deposited on PET Substrates

2009 ◽  
Vol 79-82 ◽  
pp. 883-886
Author(s):  
Yu Hui Zhang ◽  
Quan Ji ◽  
Xi Hua Pei
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Surface Morphology ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
Structure Study ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Titanium Dioxide Thin Films ◽  
Pet Substrate

Titanium dioxide (TiO2) thin films were deposited by rf magnetron sputtering, using a Ti target (purity 99.99%), on poly (ethylene terephthalate) (PET) substrate. Argon and oxygen were used as the working and reacting gas, respectively. The surface morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the film composition and structure by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Uniform and compact TiO2 nanoparticles with diameter about 50 nm were deposited on PET substrates within 2 minutes. Many nano-sized particles aggregated and formed larger clusters after 5 minutes. The size of the clusters increased with increased sputtering time. The particles grew perpendicular to the substrate, and the surfaces of the films were smooth and undulate. The Ti2p peak was resolvable into the three valence species Ti4+, Ti3+ and Ti2+. The O/Ti ratio varied with the Ar: O2, ratio, the optimum value of which was in the range 4-8. The TiO2 films deposited on PET substrate were amorphous.

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