The Role of Charged Gap States in Light-Induced Degradation of Single-Junction a-Si:H Solar Cells

2004 ◽  
Vol 808 ◽  
Author(s):  
M. Zeman ◽  
V. Nádazdy ◽  
J.W. Metselaar
Keyword(s):  
Solar Cells ◽  
Deep Level ◽  
Spectral Response ◽  
State Density ◽  
Single Junction ◽  
Transient Spectroscopy ◽  
Gap States ◽  
Hydrogenated Amorphous ◽  
Positively Charged

ABSTRACTComputer simulations of single-junction hydrogenated amorphous silicon (a-Si:H) solar cells with different thickness of the intrinsic layer were carried out in order to study the role of charge gap states in their light-induced degradation. It is demonstrated that it is the decrease of positively charged states above midgap, Dh, and the increase of neutral states around midgap,Dz, and negatively charged states below midgap, De in the intrinsic layer that result in a drop of performance of the solar cells due to light soaking. These changes in the gap states are in accordance with our recent experimental results from the charge deep-level transient spectroscopy on undoped a-Si:H. The experimentally observed changes in the dark and illuminated J-V curves and spectral response could not be simulated with the same set of input parameters by only increasing the defect-state density in the intrinsic layer.

Evolution of Charged Gap Statesin a- Si:H Under Light Exposure

2003 ◽  
Vol 762 ◽  
Author(s):  
M. Zeman ◽  
V. Nádaždy ◽  
R.A.C.M.M. van Swaaij ◽  
R. Durný ◽  
J.W. Metselaar
Keyword(s):  
Deep Level ◽  
Light Exposure ◽  
Dark Conductivity ◽  
Initial Energy ◽  
Energy Distributions ◽  
Transient Spectroscopy ◽  
Induced Changes ◽  
Hydrogenated Amorphous ◽  
Kinetics Of ◽  
Positively Charged

AbstractThe charge deep-level transient spectroscopy (Q-DLTS) experiments on undoped hydrogenated amorphous silicon (a-Si:H) demonstrate that during light soaking the states in the upper part of the gap disappear, while additional states around and below midgap are created. Since no direct correlation is observed in light-induced changes of the three groups of states that we identify from the Q-DLTS signal, we believe that we deal with three different types of defects. Positively charged states above midgap are related to a complex formed by a hydrogen molecule and a dangling bond. Negatively charged states below midgap are attributed to floating bonds. Various trends in the evolution of dark conductivity due to light soaking indicate that the kinetics of light-induced changes of the three gap-state components depend on their initial energy distributions and on the spectrum and intensity of light during exposure.

Space Radiation Effects in Advanced Solar Cell Materials and Devices

2001 ◽  
Vol 692 ◽  
Author(s):  
R. J. Walters ◽  
G. P. Summers
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Radiation Effects ◽  
Deep Level ◽  
Spectral Response ◽  
Cell Structure ◽  
Electrical Performance ◽  
Internal Cell ◽  
Particle Irradiation ◽  
Transient Spectroscopy

AbstractAn investigation of the physical mechanisms governing the response of III-V based solar cells to particle irradiation is presented. The effect of particle irradiation on single and multijunction solar cells is studied through current vs. voltage, spectral response, and deep level transient spectroscopy measurements. The basic radiation response mechanisms are identified, and their effects on the solar cell electrical performance are described. In particular, a detailed analysis of multijunction InxGa1-xP/InyGa1-yAs/Ge devices is presented. The MJ cell response is found to be more strongly affected by the internal cell structure than by the In content.

The role of hydrogenated amorphous silicon oxide buffer layer on improving the performance of hydrogenated amorphous silicon germanium single-junction solar cells

2016 ◽  
Vol 62 ◽  
pp. 626-631 ◽  
Author(s):  
Jaran Sritharathikhun ◽  
Sorapong Inthisang ◽  
Taweewat Krajangsang ◽  
Patipan Krudtad ◽  
Suttinan Jaroensathainchok ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Silicon Oxide ◽  
Hydrogenated Amorphous Silicon ◽  
Single Junction ◽  
Amorphous Silicon Oxide ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

On the interface quality of MIS structures fabricated from Atomic Layer Deposition of HfO2, Ta2O5 and Nb2O5−Ta2O5−Nb2O5 dielectric thin films

2003 ◽  
Vol 786 ◽  
Author(s):  
S. Dueñas ◽  
H. Castán ◽  
H. García ◽  
J. Barbolla ◽  
K. Kukli ◽  
...  
Keyword(s):  
Thin Films ◽  
Defect Density ◽  
Deep Level ◽  
Atomic Layer ◽  
Interface State ◽  
State Density ◽  
Interface Quality ◽  
Transient Spectroscopy ◽  
Gap States ◽  
Mis Structures

ABSTRACTA study of metal-insulator-semiconductor (MIS) structures based on atomic layer deposited HfO2, Ta2O5 and Nb2O5−Ta2O5−Nb2O5 thin films is presented. Our attention was focussed on interface quality and defect density in the dielectric. Interface states as well as defects inside the insulator bulk were measured by using capacitance-voltage (C-V), deep level transient spectroscopy (DLTS) and conductance transient (G-t) techniques. Nb2O5−Ta2O5−Nb2O5 based capacitors exhibit the highest interface state density, whereas the minimum is obtained for HfO2. Conductance transients are not observed in Al/HfO2/SiO2/Si stacks, thus indicating that disordered induced gap states (DIGS) are not present in these structures. We also observed that post-metallization annealing in forming gas diminishes the trap interface density at the expense of increasing DIGS in the Al/HfO2/Si cases.

Effect of Fermi Level Position in Intrinsic a-Si:H on the Evolution of Defect States under Light Exposure.

2005 ◽  
Vol 862 ◽  
Author(s):  
M. Zeman ◽  
V. Nádaždy ◽  
R. Durný ◽  
J.W. Metselaar
Keyword(s):  
Deep Level ◽  
Light Exposure ◽  
Oxide Semiconductor ◽  
Defect State ◽  
Defect States ◽  
State Distribution ◽  
Type Distribution ◽  
Transient Spectroscopy ◽  
Hydrogenated Amorphous ◽  
Positively Charged

AbstractThe evolution of the programmed defect-state distributions in intrinsic hydrogenated amorphous silicon (a-Si:H) due to light soaking was qualitatively determined from charge deep-level transient spectroscopy. The defect-state distribution in a-Si:H was programmed by applying a particular bias voltage on the metal-oxide-semiconductor structure while annealing the structure above the equilibration temperature. The programmed distributions simulate defect-state distributions in different parts of an actual a-Si:H solar cell, particularly in the intrinsic regions close to the p/i and i/n interfaces.The defect-state distribution in the bulk of the intrinsic layer is characterized by comparable contributions from the positively charged defect states above midgap, Dh, neutral states, Dz, and negatively charged states below midgap, De. In the programmedp-type (n-type) defect-state distribution there is an excess of the Dh (De) states. Light exposure modifies the p-type distribution that evolves to a broad distribution of states with a maximum around midgap. This distribution is dominated by Dz states with substantial contributions from Dh and De states. In case of n-type distribution light soaking only slightly influences the distribution by removing a part of the Dh states and by a small increase of Dz and De states.

scholarly journals Pathways toWards 30% Efficient Single‐Junction Perovskite Solar Cells and the Role of Mobile Ions

Solar RRL ◽  
2021 ◽  
Author(s):  
Jonas Diekmann ◽  
Pietro Caprioglio ◽  
Moritz H. Futscher ◽  
Vincent M. Le Corre ◽  
Sebastian Reichert ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Single Junction ◽  
Mobile Ions
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