A New Up-conversion Material of Ho3+-Yb3+-Mg2+ Tri-doped TiO2 and Its Applications to Perovskite Solar Cells

Abstract

A new up-conversion nanomaterial of Ho3+-Yb3+-Mg2+ tri-doped TiO2 (UC-Mg-TiO2) was designed and synthesized with a sol-gel method. The UC-Mg-TiO2 presented enhanced up-conversion fluorescence by an addition of Mg2+. The UC-Mg-TiO2 was utilized to fabricate perovskite solar cells by forming a thin layer on the electron transfer layer. The results display that the power conversion efficiency of the solar cells based on the electron transfer layer with UC-Mg-TiO2 is improved to 16.3 from 15.2% for those without UC-Mg-TiO2. It is demonstrated that the synthesized UC-Mg-TiO2 can convert the near-infrared light to visible light that perovskite film can absorb to improve the power conversion efficiency of the devices.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2681-4) contains supplementary material, which is available to authorized users.

Research Progress on the Application of Lanthanide-Ion-Doped Phosphor Materials in Perovskite Solar Cells

“…These results propose that the UC-TiO 2 is an efficient UC material, which expanded the spectral absorptions of PVSCs from visible light to NIR. A similar group further analyzed the role of a Ho 3+ –Yb 3+ –Mg 2+ tridoped TiO 2 (UC-Mg–TiO 2 )-based UC layer in PVSCs, which changed the Fermi level of TiO 2 via doping of Mg 2+ . In the UC-Mg–TiO 2 -based PVSCs, the PCE has been increased to 16.3% from 15.2% for the control device.…”

“…A similar group further analyzed the role of a Ho 3+ −Yb 3+ −Mg 2+ tridoped TiO 2 (UC-Mg−TiO 2 )-based UC layer in PVSCs, which changed the Fermi level of TiO 2 via doping of Mg 2+ . 12 In the UC-Mg−TiO 2 -based PVSCs, the PCE has been increased to 16.3% from 15.2% for the control device. It can be proposed that the synthesized UC-Mg−TiO 2 converted the NIR light into visible light, which was absorbed by perovskite film, resulting in improved photovoltaic performances of the devices.…”

“…10 In this regard, there are some critical challenges for enhancing the PCE of PVSCs, because the commonly used hybrid perovskite materials (MAPbI limited by their bandgaps (1.55 eV), which usually absorb light with a wavelength of less than 800 nm, resulting in absorption of only 50% of solar irradiation in both the UV and nearinfrared (NIR) regions. 11,12 Furthermore, Sn-based and inorganic perovskite materials also possess a narrow spectral response compared to the whole spectrum of sunlight. Accordingly, NIR light in the solar spectrum occupies nearly 46% of solar irradiation, and it has not been sufficiently used for photoelectric conversion of PVSCs.…”

“…However, the current PVSCs utilized a relatively smaller fraction of solar photons only. , The spectral response of solar cells is generally defined as a ratio between the generation of the number of electron–hole (e–h) pairs and the number of incident photons hitting a front surface of device as a function of wavelength, which is described from its external quantum efficiency (EQE) . In this regard, there are some critical challenges for enhancing the PCE of PVSCs, because the commonly used hybrid perovskite materials (MAPbI 3 ) are limited by their bandgaps (1.55 eV), which usually absorb light with a wavelength of less than 800 nm, resulting in absorption of only 50% of solar irradiation in both the UV and near-infrared (NIR) regions. , Furthermore, Sn-based and inorganic perovskite materials also possess a narrow spectral response compared to the whole spectrum of sunlight. Accordingly, NIR light in the solar spectrum occupies nearly 46% of solar irradiation, and it has not been sufficiently used for photoelectric conversion of PVSCs. , In principle, the problem of losses in solar cells is obtained due to the following reasons: (a) photons with energy lower than that of the bandgap cannot be absorbed by the cell, which is known as sub-bandgap or transmission loss; and (b) absorbed photons with energy higher than that of the bandgap lose excess amounts of energy, which is not efficiently employed and released as heat through thermalization loss …”

Retraction: Neodymium and Praseodymium Doped Perovskite Materials for Highly Stable CuInS2‐Hole‐Transport Layer‐Based Perovskite Solar Cells

“…In addition, Ce 3þ , Sm 3þ , Eu 3þ , Tb 3þ , Dy 3þ , Er 3þ , and Yb 3þ ions are among the lanthanide ions with the suitable energy levels to emit radiation in the visible spectrum and are considered to be suitable for the doping process into the PSK material structure. [28][29][30] Due to their high optical cross sections, Pr 3þ as well as Nd 3þ ions appear to be the most appealing lanthanide ions to be applied in the doping of PSK materials. [31][32][33] To regulate the vacancies at the B-site, the heterovalent substitution of Pb 2þ with Pr 3þ and Nd 3þ is expected to result in synergistically enhanced optoelectronic characteristics of hybrid perovskites.…”