News Blog

Page 2 of 17


New Guest Post: Coding for New Researchers

Posted on Mon, Sep 24, 2018

This is the final post in the series titled "A PhD Student Condenses...", written by one of Ossila's academic collaborators, Emma Spooner (a PhD student at the University of Sheffield). Previous posts in this series focused on condensing & reviewing recent academic articles in materials science. However, this post is unlike the rest. Instead, Emma will be sharing her thoughts and dishing out some advice on a topic that should be relevant to many new researchers - coding!

 

Basic 3D surface plot, generated with matplotlib module in Python
An example of a basic 3D surface plot generated using the 'matplotlib' module in Python.

 

Coding can be an intimidating topic for many new researchers - especially to those who don't have a background in Physics. There are so many questions to start with - what programme to use? How can I start learning? How do I process large datasets? This article aims to help you navigate the world of beginner-level coding for researchers! 

The full article written by Emma Spooner can be found here - A PhD Student Condenses: Coding for New Researchers.


New Guest Post Series: "A PhD Student Condenses..."

Posted on Mon, Sep 24, 2018

We are excited to announce the start of a new 6-part series titled "A PhD Student Condenses...", where recent academic articles will be condensed and reviewed by Ossila's newest academic collaborator - Emma Spooner, a first-year PhD student in Fullerene-Free Photovoltaic Devices the University of Sheffield.

 

Condensed Summary

Title: Influence of Molar Mass Ratio, Annealing Temperature and Cathode Buffer Layer on Power Conversion Efficiency of P3HT:PC71BM-based Organic Bulk Heterojunction Solar Cell

Citation: A. Singh et. al, Organ. Electron., 2017, 51, 428-434.

Learning point: The processing conditions used for one bulk-heterojunction OPV stack may not be the most optimal for a different stack.

 

The first paper she will review in this series is an article by Singh, Dey & Iyer featured in the December 2017 issue of Organic Electronics. It is based on optimising organic  (OPV) processing conditions - a topic important in maximising power conversion efficiency (PCE) values, and therefore of particular interest to researchers in the field of OPVs.

The full post written by Emma can be found here - A PhD Student Condenses #1: The Impact of OPV Processing Conditions


New Guest Post: Introduction to Ternary Organic Solar Cells

Posted on Mon, Sep 24, 2018

This is the fifth post in a series titled "A PhD Student Condenses...", where the latest academic articles will be condensed and reviewed by one of Ossila's academic collaborators - Emma Spooner, a PhD student the University of Sheffield. If you have any feedback or want to submit a topic request for future blogposts in this series, you may do so via this online form.

 

Condensed Summary

Title: Recent Progress in Ternary Organic Solar Cells Based on Nonfullerene Acceptors

Citation: R. Yu et al., Adv. Energ. Mater., 1702814 (2018); 

DOI: 10.1002/aenm.201702814.

Learning point: Ternary organic solar cells can show boosted efficiencies, morphologies, and stability in comparison to their binary counterparts. They are especially notable for improving the performance of lower-efficiency donors. 

 

For the fifth article in her series, she will be discussing the recent work by R. Yu et al., entitled ‘Recent Progress in Ternary Organic Solar Cells Based on Nonfullerene Acceptors’1. An overview of non-fullerene acceptors in organic photovoltaics can be found in previous articles by Ossila and as part of this series.

The full post written by Emma can be found here - A PhD Student Condenses: Introduction to Ternary Organic Solar Cells.


New Guest Post: Factors Influencing OPV Stability & Degradation

Posted on Mon, Sep 24, 2018

This is the fourth post in a series titled "A PhD Student Condenses...", where the latest academic articles will be condensed and reviewed by one of Ossila's academic collaborators - Emma Spooner, a PhD student the University of Sheffield. If you have any feedback or want to submit a topic request for future blogposts in this series, you may do so via this online form.

 

Condensed Summary

Title:  Fundamentals of bulk heterojunction organic solar cells: An overview of stability/degradation issues and strategies for improvement.

Citation: S. Rafique et al., Renew. Sust. Energ. Rev. (84), 43-53 (2018).

DOI: 010.1016/j.rser.2017.12.008

Learning point: Bulk heterojunction organic solar cells are susceptible to a wide range of degradation mechanisms, including both obvious extrinsic factors, such as oxygen and humidity, and intrinsic factors. Encapsulation alone is not always sufficient to produce stable devices

 

For the fourth article in this series, she will be discussing the recent work by Rafique et al., entitled ‘Fundamentals of bulk heterojunction organic solar cells: An overview of stability/degradation issues and strategies for improvement’. A summary of the fundamental principles of solar cells can be found in this Ossila guide on solar cell theory & measurement, whilst this discussion will focus on factors influencing their stability and degradation.

The full post written by Emma Spooner can be found here -  A PhD Student Condenses: Factors Influencing OPV Stability.


New Guest Post: ITIC & Its Derivatives as OPV Acceptors

Posted on Mon, Sep 24, 2018

This is the second post in a guest series titled "A PhD Student Condenses...", where the latest academic articles will be condensed and reviewed by Ossila's newest academic collaborator - Emma Spooner, a first-year PhD student the University of Sheffield.

Condensed Summary

Title:  Effect of Non-Fullerene Acceptors’ Side Chains on the Morphology and Photovoltaic Performance of Organic Solar Cells

Citation: C. Zhang, S. Feng, Y. Liu, R. Hou, Z. Zhang, X. Xu, Y. Wu and Z. Bo, ACS Appl. Mater. Interfaces, 2017, 9, 33906-33912

DOI: 10.1021/acsami.7b09915

Learning point: Side chain modification of electron acceptors can be used to optimise bulk heterojunction morphology, and performance.

 

In the second article of this series, she will be discussing the recent work by Zhang et al. entitled ‘Effect of Non-Fullerene Acceptors’ Side Chains on the Morphology and Photovoltaic Performance of Organic Solar Cells.’1 As discussed in Ossila’s recent blogpost, non-fullerene acceptors (NFAs) are an emerging area of exciting research in organic solar cells, motivated by some of the inadequacies of conventional fullerene acceptors (such as their weak optical absorption). Further discussion of the developments in NFAs can be found in several comprehensive review articles.2-4 

The full article by Emma Spooner can be found here - A PhD Student Condenses: ITIC & Its Derivatives as OPV Acceptors

 


New Theory Guide Available: OPVs vs. 2nd-Gen Solar Cell Technologies

Posted on Tue, Sep 18, 2018

The solar cell market is currently dominated by crystalline silicon (c-Si) cells - also known as first-generation solar cells - which are lauded for their high efficiency and well-established manufacturing processes. Despite this, c-Si cells have high costs and a long payback time. As such, this type of solar cell is unlikely to be fully adopted until initial costs are lowered.

On the other hand, commercially-available thin-film solar cells (second-generation) are both affordable and easy to manufacture. This is due to their thin active layers, which use much less material than c-Si cells. They also pave the way for flexible and translucent solar cells.

graph of record efficiencies for 2nd-generation thin-film cells compared to organic photovoltaics
Record efficiencies for second-generation thin-film solar cells vs organic photovoltaics.

 

Beyond the technologies mentioned above are third-generation solar cells - which among others, includes organic photovoltaics (OPVs). This generation encompasses 'emerging' technologies that are less commercially available. OPVs are on their way to achieving efficiencies comparable to those of commercial c-Si cells, and typically have simpler manufacturing processes, higher defect tolerance, and fewer rare or toxic components.

You can learn more about the pros and cons of organic photovoltaics in comparison to second-generation solar cell technologies in our latest guide: Organic Photovoltaics vs. 2nd-Generation Solar Cell Technologies.


New Guide Available: Dip Coating Theory - Film Thickness

Posted on Tue, Sep 11, 2018

An illustration of how the dynamics of drying in dip coating are affected by the formation of a concentration gradient and the capillary action of the dry film.

 

Dip coating is a popular thin-film coating method used in both academia and industry. This method involves immersing and withdrawing a substrate from solution in a precise, controlled manner - leaving behind a thin film of solution coated on to the substrate. The thickness of this resulting thin film is directly affected by the processes and processing conditions that take place during dip coating. 

Interatcions between various combinations of forces are at play during each stage of dip coating. The two stages of dip coating that have the strongest influence on the characteristics of the thin film are the withdrawal and drying stages.

Our newest guide will give you a basic overview of dip coating. This guide also provides theoretical explanations behind the factors affecting film thickness - including wet film formation,  thickness evolution, and the dynamics of drying.

 


New Guide Available: Green OPV Solvents

Posted on Tue, Aug 14, 2018

Despite continuous improvement in the efficiencies of lab-scale organic solar cells, most devices still use aromatic halogenated solvents to dissolve active layers. Whilst good for making efficient solar cells, solvents of this type are subject to stricter regulation as they often have negative effects on the environment and human health.

This leads to a situation where the advantages of organic photovoltaics (OPVs) - low production cost and low environmental hazards - cannot be fully realised, because they clash with the disadvantages of halogenated solvents. 

 

Structures of traditional halogenated solvents, non-halogenated alternatives, and solvent additives.

 

Fortunately, this can be resolved by using environmentally-benign 'green'  solvents - a term used to describe non-halogenated solvents. The environmental accumulation of 'green' solvents is easier to manage, making them preferable for large-scale OPV manufacture.

Our latest guide - "Green Solvents for Organic Photovoltaics" explores the challenges of using 'green' solvents, explains what their use looks like in practice, and what the future might hold for environmentally-benign OPV systems.


World-leading Exciplex Layers Created by Ossila's PhD Student

Posted on Wed, Aug 01, 2018

Massive congratulations to our Excilight PhD student, Marco Collela on the publication of his recent paper: "Solution processable small molecule based TADF exciplex OLEDs (Colella, Pander, & Monkman, 2018)". Marco worked as part of a research team from Durham University. Whilst carrying out scientific research for this paper at Ossila, Marco was primarily supervised by our Senior Systems Engineer, Dr. Nick Scarratt.

 

Marco - Ossila PhD student from Excilight
Marco, Ossila's Excilight PhD student.

 

This paper has demonstrated the suitability of using small-molecule TADF exciplexes as solution-processable emissive layers for OLEDS.

 

Read more...

Interview with Our Award-Winning Student Employees!

Posted on Fri, Jul 13, 2018

Recently, a couple of our hardworking student employees - Dhilan Devadasan & Máté Lukács -  won a National award for UK Student Employee of the Year (SEOTY) in their role as Manufacturing Engineers at Ossila. They very kindly took the time to have a chat with us so you can get to know them better! 

 

Ossila's award-winning student employees - SEOTY 2018
National award winners for UK Student Employee of the Year in the Commercial Impact (Off-Campus) category. L-R: Máté & Dhilan.

 

In this casual interview, they share details on what their typical day on the job looks like, the skills they have picked up on the way, give some valuable advice, and talk about their hobbies!

 

Read more...

Page 2 of 17