scholarly journals Ultrafast Charge Generation Enhancement in Nanoscale Polymer Solar Cells with DIO Additive

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2174
Author(s):  
Tongchao Shi ◽  
Zeyu Zhang ◽  
Xia Guo ◽  
Zhengzheng Liu ◽  
Chunwei Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Vibrational Relaxation ◽  
Transient Absorption ◽  
Polymer Solar Cells ◽  
Acid Methyl Ester ◽  
Free Charge ◽  
Exciton Dissociation ◽  
Charge Generation ◽  
Carrier Generation ◽  
Acid Methyl

We study the ultrafast photoexcitation dynamics in PBDTTT-C-T (P51, poly(4,8-bis(5-(2-ethylhexyl)-thiophene-2-yl)-benzo[1,2-b:4,5-b′]dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene)) film (~100 nm thickness) and PBDTTT-C-T:PC71BM (P51:PC71BM, phenyl-C71-butyric-acid-methyl ester) nanostructured blend (∼100 nm thickness) with/without DIO(1,8-diiodooctane) additives with sub-10 fs transient absorption (TA). It is revealed that hot-exciton dissociation and vibrational relaxation could occur in P51 with a lifetime of ~160 fs and was hardly affected by DIO. However, the introduction of DIO in P51 brings a longer lifetime of polaron pairs, which could make a contribution to photocarrier generation. In P51:PC71BM nanostructured blends, DIO could promote the Charge Transfer (CT) excitons and free charges generation with a ~5% increasement in ~100 fs. Moreover, the dissociation of CT excitons is faster with DIO, showing a ~5% growth within 1 ps. The promotion of CT excitons and free charge generation by DIO additive is closely related with active layer nanomorphology, accounting for Jsc enhancement. These results reveal the effect of DIO on carrier generation and separation, providing an effective route to improve the efficiency of nanoscale polymer solar cells.

scholarly journals Aggregation Controlled Charge Generation in Fullerene Based Bulk Heterojunction Polymer Solar Cells: Effect of Additive

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 115
Author(s):  
Washat Ware ◽  
Tia Wright ◽  
Yimin Mao ◽  
Shubo Han ◽  
Jessa Guffie ◽  
...  
Keyword(s):  
Solar Cells ◽  
Polymer Blends ◽  
Transient Absorption ◽  
Polymer Solar Cells ◽  
Acid Methyl Ester ◽  
Transient Absorption Spectroscopy ◽  
Generation Process ◽  
Charge Generation ◽  
Highly Efficient ◽  
The Impact

Optimization of charge generation in polymer blends is crucial for the fabrication of highly efficient polymer solar cells. While the impacts of the polymer chemical structure, energy alignment, and interface on charge generation have been well studied, not much is known about the impact of polymer aggregation on charge generation. Here, we studied the impact of aggregation on charge generation using transient absorption spectroscopy, neutron scattering, and atomic force microscopy. Our measurements indicate that the 1,8-diiodooctane additive can change the aggregation behavior of poly(benzodithiophene-alt-dithienyl difluorobenzotriazole (PBnDT-FTAZ) and phenyl-C61-butyric acid methyl ester (PCBM)polymer blends and impact the charge generation process. Our observations show that the charge generation can be optimized by tuning the aggregation in polymer blends, which can be beneficial for the design of highly efficient fullerene-based organic photovoltaic devices.

Double-Excitation Dynamics in m-LPPP probed with sub-20 fs Time Resolution

2003 ◽  
Vol 771 ◽  
Author(s):  
C. Gadermaier ◽  
G. Cerullo ◽  
C. Manzoni ◽  
U. Scherf ◽  
E.J.W. List ◽  
...  
Keyword(s):  
Vibrational Relaxation ◽  
Broad Band ◽  
Generation Efficiency ◽  
Exciton Dissociation ◽  
Charge Generation ◽  
Carrier Generation ◽  
Dissociation Probability ◽  
Ultrafast Relaxation ◽  
First Excited State ◽  
Differential Transmission

AbstractIn a novel modification of transient differential transmission spectroscopy, the first excited state S1 is reexcited via a second laser pulse towards a higher lying state Sn. The dynamics of the relaxation of this state Sn as well as the states created from Sn are revealed by a broad-band probe pulse.We find that the charge carrier generation efficiency from Sn is higher compared to S1. The push and probe durations below 20 fs enable the temporal resolution of the ultrafast relaxation of the Sn state and enables us to identify the two main contributions to enhanced charge generation from Sn, energy migration towards sites of high dissociation probability, and exciton dissociation during vibrational relaxation.

Unraveling the Temperature Dependence of Exciton Dissociation and Free Charge Generation in Nonfullerene Organic Solar Cells

Solar RRL ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 2000789
Author(s):  
Chao Ma ◽  
Christopher C. S. Chan ◽  
Xinhui Zou ◽  
Han Yu ◽  
Jianquan Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Temperature Dependence ◽  
Organic Solar Cells ◽  
Free Charge ◽  
Exciton Dissociation ◽  
Charge Generation

scholarly journals Understanding of Photophysical Processes in DIO Additive-Treated PTB7:PC71BM Solar Cells

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1139
Author(s):  
Xiaojun Su ◽  
Rong Hu ◽  
Guanzhao Wen ◽  
Xianshao Zou ◽  
Mengyao Qing ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Time Scale ◽  
Polymer Solar Cells ◽  
Acid Methyl Ester ◽  
Device Performance ◽  
Operating Voltage ◽  
Exciton Dissociation ◽  
Carrier Recombination ◽  
Dissociation Efficiency

1,8-diiodooctane (DIO) additive is an important method for optimizing the morphology and device performance of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7)-based polymer solar cells. However, the effect of DIO additive on charge photogeneration dynamics of PTB7-based polymer solar cells is still poorly understood. In this work, the effect of DIO additive on the carrier photogeneration dynamics, as well as device performance of PTB7: [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) solar cells was studied. Bias-dependent photoluminescence (PL) experiments of a neat PTB7 device show that the exciton cannot be dissociated by the electric field in the device within the operating voltage range, but it can be effectively dissociated by the high electric field. PL and time-resolved PL studies show that DIO additive reduces the phase size of PTB7 in the blend film, resulting in an increased exciton dissociation efficiency. The carrier recombination processes were studied by transient absorption, which shows geminate carrier recombination was suppressed in the DIO-treated PTB7:PC71BM device in ultrafast time scale. The increased exciton dissociation efficiency and suppressed carrier recombination in ultrafast time scale play an important role for DIO-treated PTB7:PC71BM solar cells to attain a higher power conversion efficiency.

scholarly journals -Based Organic Hybrid Solar Cells with Doping

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Zühal Alparslan ◽  
Arif Kösemen ◽  
Osman Örnek ◽  
Yusuf Yerli ◽  
S. Eren San
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Solar Cells ◽  
Polymer Solar Cells ◽  
Acid Methyl Ester ◽  
Organic Thin Films ◽  
Efficiency Enhancement ◽  
Organic Hybrid ◽  
Acid Methyl ◽  
Mn Doped

A hybrid solar cell is designed and proposed as a feasible and reasonable alternative, according to acquired efficiency with the employment of TiO2(titanium dioxide) and Mn-doped TiO2thin films. In the scope of this work, TiO2(titanium dioxide) and Mn:TiO2hybrid organic thin films are proposed as charge transporter layer in polymer solar cells. Poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT: PCBM) is used as active layer. When the Mn-doped TiO2solar cells were compared with pure TiO2cells, Mn-doped samples revealed a noteworthy efficiency enhancement with respect to undoped-TiO2-based cells. The highest conversion efficiency was obtained to be 2.44% at the ratio of 3.5% (wt/wt) Mn doping.

Sign in / Sign up

Export Citation Format

Share Document