COPPER BASED CHALCOGENIDES

This area of research focuses on two chalcogenide materials, CZTS and CIGS, which are employed as the absorber layer in solar cells. These thin-film semi-conductors are far less material intense than current silicon based solar modules. They are almost identical in crystal structure, with the expensive rare earths indium and gallium in CIGS being replaced with cheap and abundant zinc and tin in CZTS. CIGS has achieved power conversion efficiencies (PCE) above 20% and as such, is already being procduced on an industrial scale. However, its wide-spread adoption is limited by the scarcity of its constituent elements. CZTS does not possess these problems, and is therefore being touted as the material of choice for the next generation of thin-film PV technology. Our team holds several world records for the PCE of CZTS solar cells, and one of our main research goals is to elevate it to a level where CZTS can become a commercially viable product. Our main research goals in this particular field are developing wide band gap CZTS for tandem silicon devices, selenium doped CZTS for single junction devices and CIGS based thin-film devices.

 

RESEARCH GALLERY

CZTS solar cells with over 10% power conversion efficiency enabled by heterojunction heat treatment

CZTS solar cells with over 10% power conversion efficiency enabled by heterojunction heat treatment

Recombination analysis in heat treated heterojunction CZTS solar cell

Recombination analysis in heat treated heterojunction CZTS solar cell

TEM, HAADF images and intensity profile of heat treated CZTS

TEM, HAADF images and intensity profile of heat treated CZTS

Band alignment study for heat treated CZTS

Band alignment study for heat treated CZTS

SEM image and Auger profile CZTSSe deivce

SEM image and Auger profile CZTSSe deivce

TEM image CZTS device fabricated by the sol–gel method and EDS mappings for different compositional

TEM image CZTS device fabricated by the sol–gel method and EDS mappings for different compositional

Stable chemical potential regions for CZTS (left) and CZTSe (right)

Stable chemical potential regions for CZTS (left) and CZTSe (right)

Study of Germanium doped CZTS solar cells

Study of Germanium doped CZTS solar cells

2D topography and surface spatial maps of kesterite compounds

2D topography and surface spatial maps of kesterite compounds

Over 9% Efficient Kesterite CZTS Solar Cell Fabricated by Using ZnCdS Buffer Layer

Over 9% Efficient Kesterite CZTS Solar Cell Fabricated by Using ZnCdS Buffer Layer

HADDF images and corresponding EDS elemental line scan of 9% efficient CZTS device

HADDF images and corresponding EDS elemental line scan of 9% efficient CZTS device

EDS mapping of CZTS devices with differing buffer layers

EDS mapping of CZTS devices with differing buffer layers

XPS composition profile, VB data, band bending and band alignment schematic of p-n junction with ZnC

XPS composition profile, VB data, band bending and band alignment schematic of p-n junction with ZnC

J-V characteristiscs of CZTS cell with ZnCdS buffer layer

J-V characteristiscs of CZTS cell with ZnCdS buffer layer

SEM images for two CZTS thin film devices produced via sol-gel solution

SEM images for two CZTS thin film devices produced via sol-gel solution

Raman Spectroscopy of sol-gel CZTS samples

Raman Spectroscopy of sol-gel CZTS samples