scholarly journals High-Quality ITO/Al-ZnO/n-Si Heterostructures with Junction Engineering for Improved Photovoltaic Performance

2020 ◽  
Vol 10 (15) ◽  
pp. 5285
Author(s):  
Chong Tong ◽  
Manjeet Kumar ◽  
Ju-Hyung Yun ◽  
Joondong Kim ◽  
Sung Jin Kim

A heterostructure of Sn-doped In2O3 (ITO)/Al-doped ZnO (AZO)/n-Si was proposed and studied for photovoltaics. The top ITO worked as a transparent conducting layer for excellent optical transparency and current collection. The AZO/n-Si served as the active junction and provided the built-in potential (qVbi) for the photovoltaic devices. To achieve a higher open circuit voltage (Voc), which is the main challenge for AZO/Si heterojunctions due to the junction interfacial defects, the AZO and AZO/Si junction properties were systematically investigated. By modulating the Al doping in the AZO thin films via a dual beam co-sputtering technique, the AZO/n-Si junction quality was significantly improved with qVbi increased from 0.21 eV to 0.74 eV. As a result, the Voc of our best device was enhanced from 0.14 V to 0.42 V, with a short circuit current (Jsc) of 26.04 mA/cm2 and a conversion efficiency (Eff) of 5.03%. To our best knowledge, this is the highest Voc reported for ZnO/Si heterojunctions prepared by the sputtering method. The results confirmed the validity of our proposed structure and junction engineering approach and provided new insights and opportunities for ZnO/Si heterojunction optoelectronics.

2020 ◽  
Vol 92 (2) ◽  
pp. 20901
Author(s):  
Abdul Kuddus ◽  
Md. Ferdous Rahman ◽  
Jaker Hossain ◽  
Abu Bakar Md. Ismail

This article presents the role of Bi-layer anti-reflection coating (ARC) of TiO2/ZnO and back surface field (BSF) of V2O5 for improving the photovoltaic performance of Cadmium Sulfide (CdS) and Cadmium Telluride (CdTe) based heterojunction solar cells (HJSCs). The simulation was performed at different concentrations, thickness, defect densities of each active materials and working temperatures to optimize the most excellent structure and working conditions for achieving the highest cell performance using obtained optical and electrical parameters value from the experimental investigation on spin-coated CdS, CdTe, ZnO, TiO2 and V2O5 thin films deposited on the glass substrate. The simulation results reveal that the designed CdS/CdTe based heterojunction cell offers the highest efficiency, η of ∼25% with an enhanced open-circuit voltage, Voc of 0.811 V, short circuit current density, Jsc of 38.51 mA cm−2, fill factor, FF of 80% with bi-layer ARC and BSF. Moreover, it appears that the TiO2/ZnO bi-layer ARC, as well as ETL and V2O5 as BSF, could be highly promising materials of choice for CdS/CdTe based heterojunction solar cell.


2018 ◽  
Vol 9 ◽  
pp. 1802-1808 ◽  
Author(s):  
Katherine Atamanuk ◽  
Justin Luria ◽  
Bryan D Huey

The nanoscale optoelectronic properties of materials can be especially important for polycrystalline photovoltaics including many sensor and solar cell designs. For thin film solar cells such as CdTe, the open-circuit voltage and short-circuit current are especially critical performance indicators, often varying between and even within individual grains. A new method for directly mapping the open-circuit voltage leverages photo-conducting AFM, along with an additional proportional-integral-derivative feedback loop configured to maintain open-circuit conditions while scanning. Alternating with short-circuit current mapping efficiently provides complementary insight into the highly microstructurally sensitive local and ensemble photovoltaic performance. Furthermore, direct open-circuit voltage mapping is compatible with tomographic AFM, which additionally leverages gradual nanoscale milling by the AFM probe essentially for serial sectioning. The two-dimensional and three-dimensional results for CdTe solar cells during in situ illumination reveal local to mesoscale contributions to PV performance based on the order of magnitude variations in photovoltaic properties with distinct grains, at grain boundaries, and for sub-granular planar defects.


2017 ◽  
Vol 13 ◽  
pp. 863-873 ◽  
Author(s):  
Vinila N Viswanathan ◽  
Arun D Rao ◽  
Upendra K Pandey ◽  
Arul Varman Kesavan ◽  
Praveen C Ramamurthy

A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at −5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2, were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices. Moreover, a decrease in the torsion angle between the units was also observed for the fluorinated polymer P2 due to the enhanced electrostatic interaction between the fluorine substituents and sulfur atoms, leading to a high hole mobility. The use of a fused π-bridge in polymer P3 for the enhancement of the planarity as compared to the P1 backbone was also studied. This enhanced planarity led to the highest observed mobility among the reported three polymers as well as to an improvement in the device efficiency by more than 40% for P3.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 450 ◽  
Author(s):  
Miron Krassas ◽  
Christos Polyzoidis ◽  
Pavlos Tzourmpakis ◽  
Dimitriοs M. Kosmidis ◽  
George Viskadouros ◽  
...  

A conjugated, ladder-type multi-fused ring 4,7-dithienbenzothiadiazole:thiophene derivative, named as compound ‘T’, was for the first time incorporated, within the PTB7:PC71BM photoactive layer for inverted ternary organic solar cells (TOSCs) realization. The effective energy level offset caused by compound T between the polymeric donor and fullerene acceptor materials, as well as its resulting potential as electron cascade material contribute to an enhanced exciton dissociation, electron transfer facilitator and thus improved overall photovoltaic performance. The engineering optimization of the inverted TOSC, ITO/PFN/PTB7:Compound T(5% v/v):PC71BM/MoO3/Al, resulted in an overall power conversion efficiency (PCE) of 8.34%, with a short-circuit current density (Jsc) of 16.75 mA cm−2, open-circuit voltage (Voc) of 0.74 V and a fill factor (FF) of 68.1%, under AM1.5G illumination. This photovoltaic performance was improved by approximately 12% with respect to the control binary device.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1752 ◽  
Author(s):  
Arumugam Pirashanthan ◽  
Thanihaichelvan Murugathas ◽  
Neil Robertson ◽  
Punniamoorthy Ravirajan ◽  
Dhayalan Velauthapillai

This work focused on studying the influence of dyes, including a thiophene derivative dye with a cyanoacrylic acid group ((E)-2-cyano-3-(3′,3′′,3′′′-trihexyl-[2,2′:5′,2′′:5′′,2′′′- quaterthiophene]-5-yl) acrylicacid)(4T), on the photovoltaic performance of titanium dioxide (TiO2)/poly(3-hexyl thiophene)(P3HT) solar cells. The insertion of dye at the interface improved the efficiency regardless of the dye used. However, 4T dye significantly improved the efficiency by a factor of three when compared to the corresponding control. This improvement is mainly due to an increase in short circuit current density (JSC), which is consistent with higher hole-mobility reported in TiO2/P3HT nanocomposite with 4T dye. Optical absorption data further revealed that 4T extended the spectral response of the TiO2/P3HT nanocomposite, which could also enhance the JSC. The reduced dark current upon dye insertion ensured the carrier recombination was controlled at the interface. This, in turn, increased the open circuit voltage. An optimized hybrid TiO2/P3HT device with 4T dye as an interface modifier showed an average efficiency of over 2% under-simulated irradiation of 100 mWcm−2 (1 sun) with an Air Mass 1.5 filter.


2015 ◽  
Vol 22 (06) ◽  
pp. 1550072
Author(s):  
SUDIP ADHIKARI ◽  
HIDEO UCHIDA ◽  
MASAYOSHI UMENO

In this paper, composite carbon nanotubes (C-CNTs); single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs) are synthesized using an ultrasonic nebulizer in a large quartz tube for photovoltaic device fabrication in poly-3-octyl-thiophene (P3OT)/ n - Si heterojunction solar cells. We found that the device fabricated with C-CNTs shows much better photovoltaic performance than that of a device without C-CNTs. The device with C-CNTs shows open-circuit voltage (Voc) of 0.454 V, a short circuit current density (Jsc) of 12.792 mA/cm2, fill factor (FF) of 0.361 and power conversion efficiency of 2.098 %. Here, we proposed that SWCNTs and MWCNTs provide efficient percolation paths for both electron and hole transportation to opposite electrodes and leading to the suppression of charge carrier recombination, thereby increasing the photovoltaic device performance.


2015 ◽  
Vol 787 ◽  
pp. 3-7 ◽  
Author(s):  
S. Karuppuchamy ◽  
C. Brundha

We demonstrated the construction and performance of dye-sensitized solar cells (DSCs) based on nanoparticles of TiO2coated with thin shells of MgO by simple solution growth technique. The XRD patterns confirm the presence of both TiO2and MgO in the core-shell structure. The effect of varied shell thickness on the photovoltaic performance of the core-shell structured electrode is also investigated. We found that MgO shells of all thicknesses perform as barriers that improve open-circuit voltage (Voc) of the DSCs only at the expense of a larger decrease in short-circuit current density (Jsc). The energy conversion efficiency was greatly dependent on the thickness of MgO on TiO2film, and the highest efficiency of 4.1% was achieved at the optimum MgO shell layer.


Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 54 ◽  
Author(s):  
Zhonglian Wu ◽  
Huanxiang Jiang ◽  
Xingzhu Wang ◽  
Lei Yan ◽  
Wei Zeng ◽  
...  

To investigate the influence of fluoride phenyl side-chains onto a quinoxaline (Qx) unit on the photovoltaic performance of the narrow bandgap (NBG) photovoltaic polymers, herein, two novel NBG copolymers, PBDTT-DTQx and PBDTT-DTmFQx, were synthesized and characterized. 2-ethylhexylthiothiophene-substituted benzodithiophene (BDTT), 2,3-diphenylquinoxaline (DQx) [or 2,3-bis(3-fluorophenyl)quinoxaline (DmFQx)] and 2-ethylhexylthiophene (T) were used as the electron donor (D) unit, electron-withdrawing acceptor (A) unit and π-bridge, respectively. Compared to non-fluorine substituted PBDTT-DTQx, fluoride PBDTT-DTmFQx exhibited a wide UV-Vis absorption spectrum and high hole mobility. An enhanced short-circuit current (Jsc) and fill factor (FF) simultaneously gave rise to favorable efficiencies in the polymer/PC71BM-based polymer solar cells (PSCs). Under the illumination of AM 1.5G (100 mW cm−2), a maximum power conversion efficiency (PCE) of 6.40% was achieved with an open-circuit voltage (Voc) of 0.87 V, a Jsc of 12.0 mA cm−2 and a FF of 61.45% in PBDTT-DTmFQx/PC71BM-based PSCs, while PBDTT-DTQx-based devices also exhibited a PCE of 5.43%. The excellent results obtained demonstrate that PBDTT-DTmFQx by fluorine atom engineering could be a promising candidate for organic photovoltaics.


2014 ◽  
Vol 879 ◽  
pp. 199-205 ◽  
Author(s):  
Siti Nur Fadhilah Zainudin ◽  
Markom Masturah ◽  
Huda Abdullah

Different concentrations of Ni-doped anatase TiO2 nanoparticles were prepared by ice-bath co-precipitation method to examine the effects of various Ni2+ concentrations on the power exchange mechanism in photovoltaic performances of dye-sensitized solar cells (DSSC). X-ray powder diffraction (XRD) revealed a single anatase phase present in all samples together with three times reduction of particle size with the addition of Ni2+. Nanoparticle size exhibited better uniformity under scanning electron microscopy (SEM) with an increase of Ni2+ ions. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the formation of Ti-O-Ni bonding due to sharpened and enhanced intensity of the bands in the range of 500-1000 cm-1 and 910-1030 cm-1. Ni2+ concentrations also increased both open-circuit voltage (Voc) and short-circuit current (Isc). The optimum concentration of Ni-doping obtained was at 0.075M of Ni which shows a maximum DSSC efficiency of 0.38%.


2013 ◽  
Vol 743-744 ◽  
pp. 920-925
Author(s):  
Hong Zhou Yan ◽  
Jun You Yang ◽  
Shuang Long Feng ◽  
Ming Liu ◽  
Jiang Ying Peng ◽  
...  

TiO2 nanotubes array was fabricated by anodization. Effect of reaction duration on the morphology of TiO2 nanotube arrays was studied detailedly. The structure and morphology of the prepared nanotubes array was characterized by X-ray diffraction and scanning electron microscopy, respectively. The fabricated TiO2 arrays were peeled off and adhered to FTO glass with adhesive (mixture of tetrabutyl titanate and polyethylene glycol), then they were sintered at 450 for photoanode of DSSC. The photovoltaic performance of the prepared sample as the DSSC anode was investigated. An open circuit voltage of 0.69V and a short circuit current density of 7.78mA/cm2 were obtained, and the fill factor and the convert efficiency were 0.517 and 2.78%, respectively.


Sign in / Sign up

Export Citation Format

Share Document