Goodwill - Schedule of Goodwill (Details) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Goodwill [Line Items]
Beginning balance	$ 6,633,000
Goodwill	13,595,000	$ 13,595,000
Accumulated impairment losses	(6,962,000)	(6,962,000)
Ending Balance	6,633,000	6,633,000
Impairment of goodwill	0
Net exchange differences	0
Semiconductor
Goodwill [Line Items]
Impairment of goodwill	0
SiC/LED
Goodwill [Line Items]
Impairment of goodwill	0
Net Goodwill-Continuing Operations
Goodwill [Line Items]
Beginning balance	6,633,000
Goodwill	10,228,000	10,228,000
Accumulated impairment losses	(3,595,000)	(3,595,000)
Ending Balance	6,633,000	6,633,000
Impairment of goodwill	0
Net exchange differences	0
Net Goodwill-Continuing Operations | Semiconductor
Goodwill [Line Items]
Beginning balance	5,905,000
Goodwill	5,905,000	5,905,000
Accumulated impairment losses	0	0
Ending Balance	5,905,000	5,905,000
Impairment of goodwill	0
Net exchange differences	0
Net Goodwill-Continuing Operations | SiC/LED
Goodwill [Line Items]
Beginning balance	728,000
Goodwill	728,000	728,000
Accumulated impairment losses	0	0
Ending Balance	728,000	728,000
Impairment of goodwill	0
Net exchange differences	0
Net Goodwill-Continuing Operations | Automation
Goodwill [Line Items]
Beginning balance	0
Goodwill	3,595,000	3,595,000
Accumulated impairment losses	(3,595,000)	(3,595,000)
Ending Balance	0	0
Impairment of goodwill	0
Net exchange differences	0
Discontinued Operations
Goodwill [Line Items]
Beginning balance	0
Goodwill	3,367,000	3,367,000
Accumulated impairment losses	(3,367,000)	(3,367,000)
Ending Balance	0	$ 0
Impairment of goodwill	0
Net exchange differences	$ 0