Silicon Crystal Growth Technology Forum 2018

Improving efficiency and reducing costs is the consistent direction of PV industry. In recent years, a series of PV technological innovations from silicon wafers, cells to modules have continuously improved the conversion efficiency and reduced the LCOE. Under this background, improving and optimizing silicon crystal growth technology such as monocrystal pulling ingot, multicrystal and monolike crystal casting ingots, and producing higher quality and lower cost silicon ingots, are important to enhance PV competitiveness and realize the grid parity.

Monocrystal pulling ingot technology is transitioning from Recharged Czochralski (RCz) to Continuous Czocharlski (CCz). CCz needs high-quality granular polycrystalline silicon, the promotion of CCz will have a profound impact on photovoltaic-grade polysilicon production pattern. CCz also requires quartz crucibles with a lifespan of 500 hours; the localization of high-quality quartz crucibles is also an important issue.

CCz can effectively reduce the time, cost and energy consumption of monocrystal pulling, and the ingot has a more uniform and narrower distribution of resistivity, and higher quality. In addition, the automation and intelligence of monocrystal ingot production help increase productivity and optimize the crystal growth consistency. In April 2018, GCL-Poly announced that it will build 20GW CCz monocrystal production capacity in Qujing, Yunnan. In August 2018, Longi announced the signing of CCz high-efficiency monocrystal cooperation agreement with Aiko Solar.

Multicrystal casting ingot process is being upgraded from G6 ingot furnaces to G7 and even G8 technology, and while significantly increasing production capacity, it is necessary to continuously optimize hot zones, auxiliary materials, casting processes and equipment. Through advanced nucleation technology and high purity crucible, conversion efficiency can be improved and resistivity distribution optimized. And efficiency can also be improved by reducing dislocation density, oxygen content, and narrower resistivity. Ga-doped ingot can effectively reduce the LID of multi-PERC cell.

Casting mono-like crystal has the advantages of high minority carrier lifetime, low dislocation density and low cost, is the important development direction for silicon crystal manufacturing. GCL-Poly has started accepting orders for casting mono-like wafers in 2018. In addition, direct wafering technology has lower silicon consumption and energy consumption. In 2018, the average efficiency of high-efficiency cells produced by direct wafers has reached 20.5%, which has also caused widespread concern. N-type mono-Si cells have the advantages of high minority carrier lifetime, high tolerance to metal impurities, and low LID, n-type monocrystal production technology is worthy of attention.

Silicon Crystal Growth Technology Forum 2018 will be held on October 16 in Hangzhou, Zhejiang, China. The upcoming conference will discuss PV industry outlook and mono-Si & multi-Si market analysis, mono, mc, monolike and direct wafers process optimization and development prospects, CCz technical advantages and application prospects, demand analysis of CCz for granular polysilicon and high performance crucible, silicon crystal ingot safety production and intelligent manufacturing, high-performance auxiliary materials for monocrystal and multicrystal ingots, etc.

A.Topics:

PV industry outlook and mono-Si & multi-Si market analysis
Mono, mc, monolike and direct wafers development prospects
CCz technical advantages and application prospects
Demand analysis of CCz for granular polysilicon and high performance crucible
FBR technology to produce high quality granular polysilicon
N-type monocrystal production technology and cost control
Monocrystal pulling ingot process optimization and oxygen & carbon content reduction
High-performance auxiliary materials for monocrystal ingot:high purity quartz, graphite and C/C crucible
Multicrystal casting ingot technology upgrade - increase feed volume, reduce energy consumption and dislocation
Study on high-efficiency seeding and nucleation mechanism of multicrystal ingots
High-purity quartz and advanced furnace coating technology for reducing multicrystal ingots impurities
Monocrystal and multicrystal production technology perfectly matching DWS wafers and PERC
Direct wafering technology to produce HE multi-Si wafers and cells
Competitive analysis and technical optimization potential of monolike casting ingots
Silicon crystal ingot safety production and intelligent manufacturing
Solving mono and multi cells LID problem from silicon crystal manufacturing level