Nanostructures of silicon are gradually becoming hot candidate due to outstanding capability for trapping light and improving conversion efficiency of solar cell. In this paper, silicon nanowires（SiNWs） and silicon ...Nanostructures of silicon are gradually becoming hot candidate due to outstanding capability for trapping light and improving conversion efficiency of solar cell. In this paper, silicon nanowires（SiNWs） and silicon inverted pyramid arrays（SiIPs） were introduced on surface of Gr-Si solar cell through silver and copper-catalyzed chemical etching, respectively. The effects of SiNWs and SiIPs on carrier lifetime, optical properties and efficiency of Gr-SiNWs and Gr-SiIPs solar cells were systematically analyzed. The results show that the inverted pyramid arrays have more excellent ability for balancing antireflectance loss and surface area enlargement. The power conversion efficiency（PCE） and carrier lifetime of Gr-SiIPs devices respectively increase by 62% and 34% by comparing with that of Gr-SiNWs solar cells. Finally, the Gr-SiIPs cell with PCE of 5.63% was successfully achieved through nitric acid doping. This work proposes a new strategy to introduce the inverted pyramid arrays for improving the performance of Gr-Si solar cells.展开更多
Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane...Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane patterned sapphire substrates(PSS)by metal organic vapor phase epitaxy(MOVPE).The influences of growth conditions on the surface morphol-ogy are experimentally studied and explained by Wulff constructions.The competition of growth rate among{0001},{1011},and{1122}facets results in the various surface morphologies of GaN.A higher growth temperature of 985 ℃ and a lowerⅤ/Ⅲratio of 25 can expand the area of{}facets in GaN inverted pyramids.On the other hand,GaN inverted pyramids with almost pure{}facets are obtained by using a lower growth temperature of 930℃,a higherⅤ/Ⅲratio of 100,and PSS with pattern arrangement perpendicular to the substrate primary flat.展开更多
In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interf...In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interface in this structure, is given according to the experiment. The results show that the inverted pyramids surface has a low refection about 8%, in the anisotropic etching 70 ℃, 5% TMAH concentration, corrosion time of 90 min or 30 rain. Low refection means high light emitting rate. Most of the structure and manufacturing process can be compatible with planar CMOS technology, which makes the silicon LED greater potential for development in the future.展开更多
Microelectronic magnetic sensors are essential in diverse applications,including automotive,industrial,and consumer electronics.Hall-effect devices hold the largest share of the magnetic sensor market,and they are par...Microelectronic magnetic sensors are essential in diverse applications,including automotive,industrial,and consumer electronics.Hall-effect devices hold the largest share of the magnetic sensor market,and they are particularly valued for their reliability,low cost and CMOS compatibility.This paper introduces a novel 3-axis Hall-effect sensor element based on an inverted pyramid structure,realized by leveraging MEMS micromachining and CMOS processing.The devices are manufactured by etching the pyramid openings with TMAH and implanting the sloped walls with n-dopants to define the active area.Through the use of various bias-sense detection modes,the device is able to detect both in-plane and out-of-plane magnetic fields within a single compact structure.In addition,the offset can be significantly reduced by one to three orders of magnitude by employing the current-spinning method.The device presented in this work demonstrated high in-plane and out-of-plane current-and voltage-related sensitivities ranging between 64.1 to 198 V A−1 T−1 and 14.8 to 21.4 mV V^(−1) T−1,with crosstalk below 4.7%.The sensor exhibits a thermal noise floor which corresponds to approximately 0:5μT/√Hz p at 1.31 V supply.This novel Hall-effect sensor represents a promising and simpler alternative to existing state-of-the-art 3-axis magnetic sensors,offering a viable solution for precise and reliable magnetic field sensing in various applications such as position feedback and power monitoring.展开更多
基金support of this work from the NSFC (Nos. 51504117, 61764009 and 51762043)Yunnan Applied Basic Research Project (No. Y0120150138)Research Fund of Yunnan Province Collaborative Innovation Center (No. 2014XTZS009)
文摘Nanostructures of silicon are gradually becoming hot candidate due to outstanding capability for trapping light and improving conversion efficiency of solar cell. In this paper, silicon nanowires（SiNWs） and silicon inverted pyramid arrays（SiIPs） were introduced on surface of Gr-Si solar cell through silver and copper-catalyzed chemical etching, respectively. The effects of SiNWs and SiIPs on carrier lifetime, optical properties and efficiency of Gr-SiNWs and Gr-SiIPs solar cells were systematically analyzed. The results show that the inverted pyramid arrays have more excellent ability for balancing antireflectance loss and surface area enlargement. The power conversion efficiency（PCE） and carrier lifetime of Gr-SiIPs devices respectively increase by 62% and 34% by comparing with that of Gr-SiNWs solar cells. Finally, the Gr-SiIPs cell with PCE of 5.63% was successfully achieved through nitric acid doping. This work proposes a new strategy to introduce the inverted pyramid arrays for improving the performance of Gr-Si solar cells.
基金the National Key Research and Development Program(2021YFA0716400)the National Natural Science Foundation of China(62225405,62350002,61991443)+1 种基金the Key R&D Project of Jiangsu Province,China(BE2020004)the Collaborative Innovation Centre of Solid-State Lighting and Energy-Saving Electronics.
文摘Growth of gallium nitride(GaN)inverted pyramids on c-plane sapphire substrates is benefit for fabricating novel devices as it forms the semipolar facets.In this work,GaN inverted pyramids are directly grown on c-plane patterned sapphire substrates(PSS)by metal organic vapor phase epitaxy(MOVPE).The influences of growth conditions on the surface morphol-ogy are experimentally studied and explained by Wulff constructions.The competition of growth rate among{0001},{1011},and{1122}facets results in the various surface morphologies of GaN.A higher growth temperature of 985 ℃ and a lowerⅤ/Ⅲratio of 25 can expand the area of{}facets in GaN inverted pyramids.On the other hand,GaN inverted pyramids with almost pure{}facets are obtained by using a lower growth temperature of 930℃,a higherⅤ/Ⅲratio of 100,and PSS with pattern arrangement perpendicular to the substrate primary flat.
文摘In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interface in this structure, is given according to the experiment. The results show that the inverted pyramids surface has a low refection about 8%, in the anisotropic etching 70 ℃, 5% TMAH concentration, corrosion time of 90 min or 30 rain. Low refection means high light emitting rate. Most of the structure and manufacturing process can be compatible with planar CMOS technology, which makes the silicon LED greater potential for development in the future.
文摘Microelectronic magnetic sensors are essential in diverse applications,including automotive,industrial,and consumer electronics.Hall-effect devices hold the largest share of the magnetic sensor market,and they are particularly valued for their reliability,low cost and CMOS compatibility.This paper introduces a novel 3-axis Hall-effect sensor element based on an inverted pyramid structure,realized by leveraging MEMS micromachining and CMOS processing.The devices are manufactured by etching the pyramid openings with TMAH and implanting the sloped walls with n-dopants to define the active area.Through the use of various bias-sense detection modes,the device is able to detect both in-plane and out-of-plane magnetic fields within a single compact structure.In addition,the offset can be significantly reduced by one to three orders of magnitude by employing the current-spinning method.The device presented in this work demonstrated high in-plane and out-of-plane current-and voltage-related sensitivities ranging between 64.1 to 198 V A−1 T−1 and 14.8 to 21.4 mV V^(−1) T−1,with crosstalk below 4.7%.The sensor exhibits a thermal noise floor which corresponds to approximately 0:5μT/√Hz p at 1.31 V supply.This novel Hall-effect sensor represents a promising and simpler alternative to existing state-of-the-art 3-axis magnetic sensors,offering a viable solution for precise and reliable magnetic field sensing in various applications such as position feedback and power monitoring.
