Light Soaking and Thermal Annealing Effects on the Micro-Electrical Properties of Amorphous and Nanocrystalline Mixed-phase Silicon Solar Cells

2007 ◽  
Vol 989 ◽  
Author(s):  
Chunsheng Jiang ◽  
B. Yan ◽  
H. R. Moutinho ◽  
M. M. Al-Jassim ◽  
J. Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Open Circuit ◽  
Mixed Phase ◽  
Silicon Solar Cells ◽  
Initial State ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Local Current ◽  
Annealing Effects

AbstractWe report on the measurement of local current flow in hydrogenated amorphous and nanocrystalline mixed-phase n-i-p silicon solar cells in the initial, light-soaked, and annealed states using conductive atomic force microscopy (C-AFM). The C-AFM measurement shows that the nanometer-size grains aggregate, and the local current densities in the nanocrystalline aggregation areas decreased significantly after light soaking and recovered to values similar to the initial state after annealing at a high temperature in a vacuum. This result supports the model of two parallel-connected diodes for explaining the light-induced open-circuit voltage increase in the mixed-phase solar cells.

Local Current Flow in Mixed-Phase Silicon Solar Cells and Correlation to Light-Induced Open-Circuit Voltage Enhancement

2006 ◽  
Vol 910 ◽  
Author(s):  
Baojie Yan ◽  
C.-S. Jiang ◽  
H. R. Moutinho ◽  
M. M. Al-Jassim ◽  
Jeffrey Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Current Flow ◽  
Volume Fraction ◽  
Cell Structure ◽  
Open Circuit ◽  
Phase Region ◽  
Mixed Phase ◽  
High Current ◽  
Conductive Atomic Force Microscopy ◽  
Local Current

AbstractWe use conductive atomic force microscopy (C-AFM) to measure the local current flow in the mixed-phase hydrogenated silicon n-i-p solar cell structure without the top ITO contact. The forward biased C-AFM images reveal that for the fully amorphous region the current is very low on the entire surface. However, high current spikes appear in the mixed-phase region, where the current spikes are correlated to the formation of nanocrystallite aggregations with a diameter of ~500 nm. Furthermore, the density of the current spikes increases from the mixed-phase to the substantially nanocrystalline regions. The nanocrystallite aggregation supports our previously proposed parallel-connected two-diode model for Voc drops with crystalline volume fraction and light-induced Voc increase in the mixed-phase solar cells. Adding a 50-nm thick a-Si:H buffer layer between the p and i layers significantly reduces the magnitude of the high current spikes, even the top morphology appears unaffected. This result is also consistent with the previously proposed two-diode model for explaining the carrier transport in the mixed-phase solar cells.

Kinetics of Light-Induced Effects in Mixed-Phase Hydrogenated Silicon Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Guozhen Yuea ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Equivalent Circuit Model ◽  
Open Circuit ◽  
Mixed Phase ◽  
Silicon Solar Cells ◽  
Initial Increase ◽  
Soaking Time ◽  
Hydrogenated Silicon ◽  
Kinetics Of

AbstractWe have observed a significant light-induced increase in the open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells. In this study, we investigate the kinetics of the light-induced effects. The results show that the cells with different initial Voc have different kinetic behavior. For the cells with a low initial Voc (less than 0.8 V), the increase in Voc is slow and does not saturate for light-soaking time of up to 16 hours. For the cells with medium initial Voc (0.8 ∼ 0.95 V), the Voc increases rapidly and then saturates. Cells with high initial Voc (0.95 ∼ 0.98 V) show an initial increase in Voc, followed bya Voc decrease. All light-soaked cells exhibit a degradation in fill factor. The temperature dependence of the kinetics shows that light soaking at high temperatures causes Voc increase to saturate faster than at low temperatures. The observed results can be explained by our recently proposed two-diode equivalent-circuit model for mixed-phase solar cells.

Emerging Conductive Atomic Force Microscopy for Metal Halide Perovskite Materials and Solar Cells

2020 ◽  
Vol 10 (10) ◽  
pp. 1903922 ◽  
Author(s):  
Haonan Si ◽  
Suicai Zhang ◽  
Shuangfei Ma ◽  
Zhaozhao Xiong ◽  
Ammarah Kausar ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Solar Cells ◽  
Metal Halide ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Perovskite Materials ◽  
Metal Halide Perovskite ◽  
Halide Perovskite

Micro-Raman Studies of Mixed-phase Hydrogenated Silicon Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Jessica M. Owens ◽  
Daxing Han ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Kenneth Lord ◽  
...  
Keyword(s):  
Solar Cells ◽  
Direct Evidence ◽  
Amorphous Material ◽  
Equivalent Circuit Model ◽  
Open Circuit ◽  
Mixed Phase ◽  
Silicon Solar Cells ◽  
Heterogeneous Structure ◽  
Hydrogenated Silicon ◽  
A Cell

AbstractThe open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells has been found to increase after light soaking. In this study, we use micro-Raman to investigate the heterogeneous structure of solar cells in the amorphous-to-nanocrystalline transition region. For a cell with Voc = 0.981 V, Raman spectra show a typical broad Gaussian lineshape around 480 cm-1, a signature of typical amorphous material. A cell with Voc = 0.674 V displays a sharp Lorentzian peak around 516 cm-1, indicative of nanocrystallinity. A cell with Voc = 0.767 V was systematically scanned for 20 different positions in 500 μm increments. Most spectra show a typical Gaussian lineshape around 480 cm-1, several spectra reveal a hint of a nanocrystalline shoulder around 512 cm-1, and one spectrum exhibits a distinct nanocrystalline peak. We conclude that the nanocrystallite distribution in the mixed-phase material is very non-uniform even within a mm dot. This result provides direct evidence supporting a recently proposed two-diode equivalent-circuit model to explain the light-induced effect.

SELF-ASSEMBLED Ge-DOTS FOR Si SOLAR CELLS

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4347-4351 ◽  
Author(s):  
H. PRESTING ◽  
J. KONLE ◽  
H. KIBBEL
Keyword(s):  
Solar Cells ◽  
Open Circuit Voltage ◽  
Elevated Temperatures ◽  
Growth Conditions ◽  
Open Circuit ◽  
3 Dimensional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
P Type

Silicon solar cells with embedded germanium (Ge) layers deposited as 3-dimensional islands in the Stranski-Krastanov growth mode have been grown by molecular beam epitaxy (MBE) to enhance the efficiency of Si thin film solar cells. The Ge-layers increase the infrared absorption in the base of the cell to achieve higher photocurrent which should overcome the loss in the open circuit voltage due to incorporation of a smaller bandgap material in the heterostructure. Up to 75 layers of Ge, each about 8 monolayers (ML) thick, separated by Si-spacer layers (9-18nm) have been deposited at rather elevated temperatures (700°C) on a standard 10Ωcm p-type Si-substrate. Island densities of 1011 cm -2 have been achieved by use of antimony (Sb) as surfactant. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used to characterize the growth of Ge-islands under variuos growth conditions. Photocurrent measurements exhibit a higher photo-response in the infrared regime but a lower open circuit voltage of the fabricated solar cells compared to a Si-reference cell.

Microscopic Characterizations of Nanostructured Silicon Thin Films for Solar Cells

2011 ◽  
Vol 1321 ◽  
Author(s):  
Antonín Fejfar ◽  
Petr Klapetek ◽  
Jakub Zlámal ◽  
Aliaksei Vetushka ◽  
Martin Ledinský ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Maxwell Equations ◽  
Amorphous Matrix ◽  
Optical Power ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Silicon Thin Films ◽  
Atomic Force

ABSTRACTMicroscopic characterization of mixed phase silicon thin films by conductive atomic force microscopy (C-AFM) was used to study the structure composed of conical microcrystalline grains dispersed in amorphous matrix. C-AFM experiments were interpreted using simulations of electric field and current distributions. Density of absorbed optical power was calculated by numerically solving the Maxwell equations. The goal of this study is to combine both models in order to simulate local photoconductivity for understanding the charge photogeneration and collection in nanostructured solar cells.

Electrochemical and atomic force microscopy investigations of the effect of CdS on the local electrical properties of CH3NH3PbI3:CdS perovskite solar cells

2017 ◽  
Vol 5 (46) ◽  
pp. 12112-12120 ◽  
Author(s):  
Mingxuan Guo ◽  
Fumin Li ◽  
Lanyu Ling ◽  
Chong Chen
Keyword(s):  
Atomic Force Microscopy ◽  
Solar Cells ◽  
Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Bulk Heterojunction ◽  
Perovskite Solar Cells ◽  
Kelvin Probe ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force

The effect of the incorporated CdS on the local optoelectronic properties of CH3NH3PbI3:CdS bulk heterojunction (BHJ) perovskite solar cells (PSCs) are studied using Kelvin probe force microscopy (KPFM), conductive atomic force microscopy (c-AFM) and electrochemical impedance spectroscopy (EIS).

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