scholarly journals Characterization of thin CdTe solar cells with a CdSeTe front layer

MRS Advances ◽  
2019 ◽  
Vol 4 (37) ◽  
pp. 2053-2062
Author(s):  
Alexandra M. Bothwell ◽  
Jennifer A. Drayton ◽  
Pascal M. Jundt ◽  
James R. Sites
Keyword(s):  
Current Density ◽  
Fill Factor ◽  
Alloy Layer ◽  
Time Resolved ◽  
Loss Analysis ◽  
Cdte Solar Cells ◽  
Close Space Sublimation ◽  
Device Structures ◽  
Electroluminescence Intensity ◽  
Time Resolved Photoluminescence

ABSTRACTThin CdTe photovoltaic device efficiencies show significant improvement with the incorporation of a CdSeTe alloy layer deposited between a MgZnO emitter and CdTe absorber. CdTe and CdSeTe/CdTe devices fabricated by close-space sublimation with a total absorber thickness of 1.5 µm are studied using microscopy measurements and show minimal diffusion of Se into the CdTe. Current loss analysis shows that the CdSeTe layer is the primary absorber in the CdSeTe/CdTe structure, and fill factor loss analysis shows that ideality-factor reduction is the dominant mechanism of fill factor loss. Improvement in the CdSeTe/CdTe absorber quality compared to CdTe is also reflected in spectral and time-resolved photoluminescence measurements. Current density vs. voltage measurements show an increase in current density of up to 2 mA/cm2 with the addition of CdSeTe due to a band gap shift from 1.5 to 1.42 eV for CdTe and CdSeTe/CdTe absorbers respectively. Voltage deficit is lower with the incorporation of the CdSeTe layer, corroborated by improved electroluminescence intensity. The addition of CdSeTe into CdTe device structures has increased device efficiencies from 14.7% to 15.6% for absorbers with a total thickness less than two microns.

Time-resolved photoluminescence studies of CdTe solar cells

2003 ◽  
Vol 94 (5) ◽  
pp. 3549-3555 ◽  
Author(s):  
W. K. Metzger ◽  
D. Albin ◽  
D. Levi ◽  
P. Sheldon ◽  
X. Li ◽  
...  
Keyword(s):  
Solar Cells ◽  
Time Resolved ◽  
Cdte Solar Cells ◽  
Photoluminescence Studies ◽  
Time Resolved Photoluminescence

Electron-beam damage of oxides at high current densities

1989 ◽  
Vol 47 ◽  
pp. 634-635
Author(s):  
M. R. McCartney ◽  
J. K. Weiss ◽  
David J. Smith
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Current Density ◽  
Transition Metal Oxides ◽  
Time Resolved ◽  
Rapid Acquisition ◽  
Resolution Electron ◽  
Current Densities ◽  
Electron Stimulated Desorption ◽  
Channel Analyzer

It is well-known that electron-beam irradiation within the electron microscope can induce a variety of surface reactions. In the particular case of maximally-valent transition-metal oxides (TMO), which are susceptible to electron-stimulated desorption (ESD) of oxygen, it is apparent that the final reduced product depends, amongst other things, upon the ionicity of the original oxide, the energy and current density of the incident electrons, and the residual microscope vacuum. For example, when TMO are irradiated in a high-resolution electron microscope (HREM) at current densities of 5-50 A/cm2, epitaxial layers of the monoxide phase are found. In contrast, when these oxides are exposed to the extreme current density probe of an EM equipped with a field emission gun (FEG), the irradiated area has been reported to develop either holes or regions almost completely depleted of oxygen. ’ In this paper, we describe the responses of three TMO (WO3, V2O5 and TiO2) when irradiated by the focussed probe of a Philips 400ST FEG TEM, also equipped with a Gatan 666 Parallel Electron Energy Loss Spectrometer (P-EELS). The multi-channel analyzer of the spectrometer was modified to take advantage of the extremely rapid acquisition capabilities of the P-EELS to obtain time-resolved spectra of the oxides during the irradiation period. After irradiation, the specimens were immediately removed to a JEM-4000EX HREM for imaging of the damaged regions.

Sign in / Sign up

Export Citation Format

Share Document