Perovskites dominate the photovoltaic research community over the last two decades due to its very high absorption coefficient,electron and hole mobility.However,most of the reported solar cells constitute organic per...Perovskites dominate the photovoltaic research community over the last two decades due to its very high absorption coefficient,electron and hole mobility.However,most of the reported solar cells constitute organic perovskites which offer very high efficiency but are highly unstable.Chalcogenide perovskites like BaZrS_(3),CaZrS_(3),etc.promise to be a perfect alternate owing to its high stability and mobilities.But,till now no stable photovoltaic device has been successfully fabricated using these materials and the existing challenges present in the synthesis of such perovskites are discussed.Also,the basic thermodynamic aspects that are essential for formation of BaZrS_(3)are discussed.An extensive review on the precedent literatures and the future direction in the BaZrS_(3)photovoltaic device research is clearly given.展开更多
Fluorite-structured oxides constitute an important category of oxides with a wide range of high-temperature applications.Following the concept of high entropy,high-entropy fluorite oxides(HEFOs)have showcased intrigui...Fluorite-structured oxides constitute an important category of oxides with a wide range of high-temperature applications.Following the concept of high entropy,high-entropy fluorite oxides(HEFOs)have showcased intriguing high-temperature application potential.However,unlocking this potential necessitates an assessment of their long-term stability under high-temperature conditions.In this study,we conducted a prolonged heat treatment at 1000℃on typical HEFO,specifically(CeHfZrGdLa)O_(x).After 100 h,high-intensity X-ray diffraction(XRD)revealed a transition from a single-phase fluorite to a multi-phase configuration.Further investigation by analytical electron microscoy(AEM)demonstrated that this degradation resulted from facilitated element diffusion and consequent escalating chemical fluctuation at high temperatures,leading to spontaneous segregation and separation of Ce and La elements,forming Ce-rich,La-poor,and La-rich phases.Notably,the La-rich phase spontaneously transformed from a fluorite structure(space group Fm3m)to a bixbyite structure(space group Ia3)at elevated temperatures,resulting in the appearance of superstructure reflection in XRD profiles and electron diffraction patterns.Despite the intricate phase decomposition,the energy band gap showed minimal variation,suggesting potential property stability of(CeHfZrGdLa)O_(x)across a broad range of compositions.These findings offer valuable insights into the future applications of HEFOs.展开更多
文摘Perovskites dominate the photovoltaic research community over the last two decades due to its very high absorption coefficient,electron and hole mobility.However,most of the reported solar cells constitute organic perovskites which offer very high efficiency but are highly unstable.Chalcogenide perovskites like BaZrS_(3),CaZrS_(3),etc.promise to be a perfect alternate owing to its high stability and mobilities.But,till now no stable photovoltaic device has been successfully fabricated using these materials and the existing challenges present in the synthesis of such perovskites are discussed.Also,the basic thermodynamic aspects that are essential for formation of BaZrS_(3)are discussed.An extensive review on the precedent literatures and the future direction in the BaZrS_(3)photovoltaic device research is clearly given.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.52150610487 and 51850410501).The authors acknowledge the help of Dr.Linlin Ma for UV-Vis spectra from the Instrumental Analytical Center of Shanghai Jiao Tong University.
文摘Fluorite-structured oxides constitute an important category of oxides with a wide range of high-temperature applications.Following the concept of high entropy,high-entropy fluorite oxides(HEFOs)have showcased intriguing high-temperature application potential.However,unlocking this potential necessitates an assessment of their long-term stability under high-temperature conditions.In this study,we conducted a prolonged heat treatment at 1000℃on typical HEFO,specifically(CeHfZrGdLa)O_(x).After 100 h,high-intensity X-ray diffraction(XRD)revealed a transition from a single-phase fluorite to a multi-phase configuration.Further investigation by analytical electron microscoy(AEM)demonstrated that this degradation resulted from facilitated element diffusion and consequent escalating chemical fluctuation at high temperatures,leading to spontaneous segregation and separation of Ce and La elements,forming Ce-rich,La-poor,and La-rich phases.Notably,the La-rich phase spontaneously transformed from a fluorite structure(space group Fm3m)to a bixbyite structure(space group Ia3)at elevated temperatures,resulting in the appearance of superstructure reflection in XRD profiles and electron diffraction patterns.Despite the intricate phase decomposition,the energy band gap showed minimal variation,suggesting potential property stability of(CeHfZrGdLa)O_(x)across a broad range of compositions.These findings offer valuable insights into the future applications of HEFOs.
