Inverted vs standard PTB7:PC70BM organic photovoltaic devices. The benefit of highly selective and extracting contacts in device performance

TLDR: In this paper, the authors compared the photovoltaic performance of different cell designs, standard and inverted, for one of the most promising systems to achieve power conversion efficiencies over 10% in polymer:fullerene single cells, namely PTB7:PC70BM.

About: This article is published in Organic Electronics.The article was published on 2014-11-01 and is currently open access. It has received 47 citations till now. The article focuses on the topics: Equivalent series resistance.

Figures

Figure 4: Left) Carrier density values as a function of the applied bias extracted from CE measurements for standard (circles) and inverted (squares) devices. The fitting of the experimental data to a first order exponential is also shown (solid lines). Right) Charge carrier lifetimes at different carrier densities.

Figure 3: Fitting results, resistance (right) and capacitive (left) data, for IS measurements performed at 1 Sun light intensity for standard (circles) and inverted (squares) using the equivalent circuits given in Fig. SI2. The chemical capacitance

Figure 2: Up) IS response for standard (left) and inverted (right) devices measured under 1 Sun and at applied bias of 0.55 V. Down) Capacitance-Frequency spectra for standard (left) and inverted (right) devices measured under 1 Sun at selected DC applied bias. The

Figure 1: Left) J-V curve for the standard device design ITO/PEDOT:PSS/PTB7:PC70BM/Ca/Ag (squares) and inverted ITO/ZnO/PTB7:PC70BM/MoO3/Ag (circles). Inset: Dark J-V curves for the same

Table 1. Figure of merits for standard and inverted devices whose J-V curves are shown in Fig. 1

Frequently asked questions

Q1. What contributions have the authors mentioned in the paper "Inverted vs standard ptb7:pc70bm organic photovoltaic devices. the benefit of highly selective and extracting contacts in device performance" ?

In this paper, the authors showed that the overall device efficiency is a balance between the recombination kinetics in the bulk of the active layer, undesired resistance to transport of carriers and leakage current due to low selectivity of the contacts.