In this section

Research

Research Focus
Experimental Techniques

Research Focus

The Field

graph The development of renewable energy technologies has become one of modern society's key scientific challenges, and at the forefront of this investigative drive is photovoltaics, the direct conversion of sunlight to electricity. Current photovoltaic modules are typically based upon silicon and their manufacturing cost hampers their accelerated global roll-out, necessitating the development of a cheaper photovoltaic alternative.

Our Work

Our research focuses upon this area of solar energy conversion, specifically in the development of cheap, next-generation organic and hybrid architectures. We undertake investigations into the fundamental science behind new materials and device concepts with the aim of elucidating design principles that can advance technological development.

Our research is predominantely based upon using transient optical spectroscopies to probe the dynamics of photo-induced excited states in novel organic and hybrid organic-inorganic solar cells. We study the energy and electron transfer processes that occur within such devices, and these investigations are undertaken in parallel with analysis of the internal nanomorphology, as well as with device optimisation and functional characterisation.

Experimental Techniques

Technique

Description

Steady State Absorption Spectroscopy

Used as a characterisation tool for thin films or solutions.
Provides information about the wavelength and amount of light being absorbed or reflected by a material.

Steady State Photoluminescence Spectroscopy

Used as a characterisation tool for thin films or solutions.
Measures the light emitted from a sample after a monochromatic excitation.
Useful for measuring the amount of exciton quenching in two-component systems.

Nuclear Magnetic Resonance Spesctroscopy

Used as a characterisation tool for understanding the composition and chemistry of electronic materials
Measures the response of spin active nuclei to a magnetic field
Useful for identifying degredation products, the presence of interactions and the oxidation states of compounds.
A combination of ¹H, ¹³C, ⁷Li, ¹¹⁹Sn and ¹³F techniques are avaliable.

Attenuated-total-reflectance Fourier Transform Infrared Spectroscopy

Vibrational spectroscopy technique allows for better understanding of structure, composition and interactions.
Can measure either solid state powders, films or liquid samples.

Transient Absorption Spectroscopy

Used as characterisation tool typically on blends or bilayers of thin films.
Measures the time-resolved absorption of polarons.
Useful for providing information about the efficiency of charge generation and also recombination processes.

Ultrafast Transient Photoluminescence Spectrosopy

This provides a time resolved photoluminescence measurement of solutions or thin films.
Has a resolution of ~120 femtoseconds.

Solar Cell Characterisation

4 solar cell testing rigs.
1 completely automated device testing rig.
Can measure device efficiency and also ICPE.

Transient Photocurrent and Photovoltage Measurements

Pulse generator with fast response LED generates a voltage / current.
Measure the time for the voltage / current to decay.
Provides insights on carrier dynamics.

Wet Lab

Lab wet lab facility containing a wide range of equipment for chemical susnthesis and thin film preparation.
Nitrogen glove box for sample annealing and storage in a nitrogen atmosphere.
Schlenk line for oxygen and water free syntheses.
Spin coater for fabrication of thin films for optical characterisation or devices.
Other equipments such as a centrifuge, a rotary evaporator and weighing balances etc.

Cleanroom

Cleanroom facility for device fabrication and testing.
Glovebox containing a solar sim and spin coater and evaporator.
Profilometer used to measure film thickness and roughness to an accuracy of 3 nm.
Clean wet lab for sample preparation
Other equipment such as oxygen plasma treatment and wire bar coaters.

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