Opto-electronic characterization of third-generation solar cells

Abstract

We present an overview of opto-electronic characterization techniques for solar cells including light-induced charge extraction by linearly increasing voltage, impedance spectroscopy, transient photovoltage, charge extraction and more. Guidelines for the interpretation of experimental results are derived based on charge drift-diffusion simulations of solar cells with common performance limitations. It is investigated how nonidealities like charge injection barriers, traps and low mobilities among others manifest themselves in each of the studied cell characterization techniques. Moreover, comprehensive parameter extraction for an organic bulk-heterojunction solar cell comprising PCDTBT:PC70BM is demonstrated. The simulations reproduce measured results of 9 different experimental techniques. Parameter correlation is minimized due to the combination of various techniques. Thereby a route to comprehensive and accurate parameter extraction is identified.

Exceptional Long Electron Lifetime in Methylammonium Lead Iodide Perovskite Solar Cell Made from Aqueous Lead Nitrate Precursor

“…The ideality factors are almost identical, which suggested that a trap‐assisted recombination mechanism occurs in both devices. Here, we disregarded shallow traps and addressed only deep traps because deep traps play a major role in Shockley–Read–Hall recombination, which affects the V OC value . The results of similar n but different recombination lifetimes strongly imply that both systems share an identical recombination mechanism (trap‐assisted recombination) but with either different amount of trapping sites or different intrinsic recombination kinetics.…”

“…Shallow traps allow carriers to undergo a continuous trapping–detrapping process during carrier transport. In this case, carriers falling into shallow traps are not freely moved, which jeopardizes the radiative recombination from free electrons and holes annihilation and photons release . We believe this protection effect of shallow traps accounts for the longer second PL lifetime in the Pb(NO 3 ) 2 /water‐perovskite film and guarantees a smooth carrier transport over the whole perovskite film.…”

“…In addition, it can be seen from Figure a that the exponential growth onset of Pb(NO 3 ) 2 /water‐based and the PbI 2 /DMF‐based devices are 0.4 and 0.8 V, respectively, which indicates that the Pb(NO 3 ) 2 /water‐based device demonstrates a considerable intraband tail stretching from the band edge to the middle of the bandgap. The midband gap energy states are considered deep traps and connected to Shockley–Read–Hall recombination …”

38.1: Quantitative Analysis of Charge Transport in Single‐Carrier Devices and OLEDs Combining DC and AC Data

“…Correlation analysis has been described in detail in previous publications. [7][8][9] In this section we will therefore focus on assessing parameter sensitivity. As an example we study a simplified hole-only device.…”

“…[3][4][5][6] Unfortunately, many of these studies have only been performed with steady-state data although it has been pointed out that the extracted parameters are highly correlated and hence less reliable. [7,8] An advantage of such a combined approach is the additional information that can be obtained from the device simulation without additional efforts. From charge density profiles one can, for example, identify bulk or interface limiting processes, [4] or judge on the quality of the charge injection contact.…”